diff --git a/src/third_party/web_platform_tests/custom-elements/concepts/custom-elements-type-allowed-chars-first-char.html b/src/third_party/web_platform_tests/custom-elements/concepts/custom-elements-type-allowed-chars-first-char.html
new file mode 100644
index 0000000..f55244e
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/concepts/custom-elements-type-allowed-chars-first-char.html
@@ -0,0 +1,59 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>First char allowed for custom element type </title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="The custom element type identifies a custom element interface and is a sequence of characters that must match the NCName production">
+<meta name="timeout" content="long">
+<link rel="help" href="https://dvcs.w3.org/hg/webcomponents/raw-file/default/spec/custom/index.html#concepts">
+<link rel="help" href="http://www.w3.org/TR/1999/REC-xml-names-19990114/#NT-NCName">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+function composeName(charCode) {
+    return String.fromCharCode(charCode) + '-x' + charCode.toString(16);
+}
+
+// NCName definition from http://www.w3.org/TR/1999/REC-xml-names-19990114/#NT-NCName
+// NCName     ::= (Letter | '_') (NCNameChar)*
+// NCNameChar ::= Letter | Digit | '.' | '-' | '_' | CombiningChar | Extender
+// Letter     ::= BaseChar | Ideographic
+
+test(function() {
+    testCharCode(getCharCode('_'), composeName, checkValidName);
+}, 'Registering valid custom element name starting with \'_\' char');
+
+test(function() {
+    baseCharsSingle.testEach(composeName, checkValidName);
+    baseCharsRanges.testEach(composeName, checkValidName);
+}, 'Registering valid custom element name starting with base char');
+
+test(function() {
+    ideographicCharsSingle.testEach(composeName, checkValidName);
+    ideographicCharsRanges.testEach(composeName, checkValidName);
+}, 'Registering valid custom element name starting with ideographic char');
+
+test(function() {
+    (new CharsArray(['.', '-', ':', '+', '='])).testEach(composeName, checkInvalidName);
+}, 'Registering custom element starting with invalid character (general) should fail');
+
+test(function() {
+    combiningChars.testEach(composeName, checkInvalidName);
+}, 'Registering custom element starting with invalid character (combining char) should fail');
+
+test(function() {
+    extenderChars.testEach(composeName, checkInvalidName);
+}, 'Registering custom element starting with invalid character (extender char) should fail');
+
+test(function() {
+    digitCharsRanges.testEach(composeName, checkInvalidName);
+}, 'Registering custom element starting with invalid character (digit char) should fail');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/concepts/custom-elements-type-allowed-chars.html b/src/third_party/web_platform_tests/custom-elements/concepts/custom-elements-type-allowed-chars.html
new file mode 100644
index 0000000..03847c6
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/concepts/custom-elements-type-allowed-chars.html
@@ -0,0 +1,55 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Chars allowed for custom element type </title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="The custom element type identifies a custom element interface and is a sequence of characters that must match the NCName production">
+<meta name="timeout" content="long">
+<link rel="help" href="https://dvcs.w3.org/hg/webcomponents/raw-file/default/spec/custom/index.html#concepts">
+<link rel="help" href="http://www.w3.org/TR/1999/REC-xml-names-19990114/#NT-NCName">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+function composeName(charCode) {
+    return 'x-' + String.fromCharCode(charCode) + '-x' + charCode.toString(16);
+}
+
+// NCName definition from http://www.w3.org/TR/1999/REC-xml-names-19990114/#NT-NCName
+// NCName     ::= (Letter | '_') (NCNameChar)*
+// NCNameChar ::= Letter | Digit | '.' | '-' | '_' | CombiningChar | Extender
+// Letter     ::= BaseChar | Ideographic
+
+test(function() {
+    baseCharsSingle.testEach(composeName, checkValidName);
+    baseCharsRanges.testEach(composeName, checkValidName);
+}, 'Registering valid custom element types with base char');
+
+test(function() {
+    ideographicCharsSingle.testEach(composeName, checkValidName);
+    ideographicCharsRanges.testEach(composeName, checkValidName);
+}, 'Registering valid custom element types with ideographic char');
+
+test(function() {
+    digitCharsRanges.testEach(composeName, checkValidName);
+}, 'Registering valid custom element types with digit chars');
+
+test(function() {
+    (new CharsArray(['.', '-', '_'])).testEach(composeName, checkValidName)
+}, 'Registering valid custom element types with characters \'.\', \'-\', \'_\'');
+
+test(function() {
+    combiningChars.testEach(composeName, checkValidName);
+}, 'Registering valid custom element types with combining char');
+
+test(function() {
+    extenderChars.testEach(composeName, checkValidName);
+}, 'Registering valid custom element types with extender char');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/concepts/custom-elements-type-naming.html b/src/third_party/web_platform_tests/custom-elements/concepts/custom-elements-type-naming.html
new file mode 100644
index 0000000..58989a2
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/concepts/custom-elements-type-naming.html
@@ -0,0 +1,66 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>The custom element type is a sequence of characters that must match the NCName production and contain a minus character</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="The custom element type is a sequence of characters that must match the NCName production and contain a U+002D HYPHEN-MINUS character">
+<link rel="help" href="https://dvcs.w3.org/hg/webcomponents/raw-file/default/spec/custom/index.html#concepts">
+<link rel="help" href="http://www.w3.org/TR/1999/REC-xml-names-19990114/#NT-NCName">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var validNames = ['x-frame', 'xx-frame', 'x--frame', '_-frame', 'x-', 'x--',
+                      'x-1', 'x-_', '_-_', '__-',  '_-1',  '_-..'];
+    HTML5_ELEMENTS.forEach(function(value) {
+        validNames.push('x-' + value);
+        validNames.push('Y-' + value.toUpperCase());
+    });
+    validNames.forEach(function(value) {
+        try {
+            doc.registerElement(value);
+        } catch (e) {
+            assert_unreached('Exception should not be thrown in case of attempt ' +
+                'to register a custom element with a name \'' + value + '\'');
+        }
+    });
+}, 'Registering valid custom element types');
+
+test(function() {
+    var doc = newHTMLDocument();
+    var invalidNames = ['xframe', 'x_frame', 'x.frame', 'x1frame', '-xframe', '1-frame',
+                        '1x-frame',	'.-frame', '_frame', 'x-f!rame', 'x-:frame'];
+    invalidNames.forEach(function(value) {
+        assert_throws('SyntaxError', function() {
+            doc.registerElement(value);
+        }, 'Exception should be thrown in case of attempt to register element ' +
+            'with the name \'' + value + '\'');
+    });
+}, 'Registering invalid custom element types should fail');
+
+test(function() {
+    var doc = newHTMLDocument();
+    var forbiddenNames = ['annotation-xml',
+                        'color-profile',
+                        'font-face',
+                        'font-face-src',
+                        'font-face-uri',
+                        'font-face-format',
+                        'font-face-name',
+                        'missing-glyph'];
+    forbiddenNames.forEach(function(value) {
+        assert_throws('SyntaxError', function() {
+            doc.registerElement(value);
+        }, 'Exception should be thrown in case of attempt to register element ' +
+            'with the name \'' + value + '\'');
+    });
+}, 'Registering forbidden custom element types should fail');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/new-registry-test.html b/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/new-registry-test.html
new file mode 100644
index 0000000..d0dc751
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/new-registry-test.html
@@ -0,0 +1,40 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>When an HTML Document is loaded in a browsing context, a new registry must be created and associated with this document</title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="When an HTML Document is loaded in a browsing context, a new registry must be created and associated with this document.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#creating-and-passing-registries">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+testInIFrame('../resources/blank.html', function(doc) {
+    try {
+        doc.registerElement('x-element');
+    } catch (e) {
+        assert_unreached('Unexpected exception, while registering a valid custom element');
+    }
+}, 'Document, loaded into browsing context, must have a new empty registry');
+
+
+testInIFrame('../resources/blank.html', function(loadedDocument) {
+    var createdDocument = document.implementation.createHTMLDocument('Test Document');
+    // Let's check that loadedDocument and createdDocument use different registeries.
+    createdDocument.registerElement('x-element');
+    try {
+        loadedDocument.registerElement('x-element');
+    } catch (e) {
+        assert_unreached('Unexpected exception while registering a custom element ' +
+            'in a document, which has it\'s own registry');
+    }
+}, 'Document, loaded into browsing context, must have a new empty registry, ' +
+        'which is different from other documents\' registries');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/no-registry-test.html b/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/no-registry-test.html
new file mode 100644
index 0000000..9cfa68b
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/no-registry-test.html
@@ -0,0 +1,49 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>New document without browsing context must not have a registry</title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="In all other cases, new documents must not have a registry.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#creating-and-passing-registries">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = document.implementation.createDocument(null, 'test', null);
+    assert_throws(
+        'NotSupportedError',
+        function() { doc.registerElement('x-element'); },
+        'Registering valid custom element in a document ' +
+            'without registry should fail');
+}, 'Document of type other than HTML, not loaded into browsing context, must not have a registry');
+
+async_test(function(t) {
+    var request = new XMLHttpRequest();
+    request.onreadystatechange = t.step_func(function() {
+        if (request.readyState == 4){
+            assert_equals(200, request.status, 'Test document is not loaded correctly');
+            var doc = request.response;
+            assert_true(doc instanceof HTMLDocument,
+                'XMLHttpRequest\'s asynchronous response should be HTML document');
+            assert_throws(
+                'NotSupportedError',
+                function() { doc.registerElement('x-element'); },
+                'Registering valid custom element in ' +
+                    'an XMLHttpRequest\'s response document should fail');
+            t.done();
+        }
+    });
+
+    request.open('GET', '../resources/blank.html', true);
+    request.responseType = 'document';
+    request.send();
+}, 'XMLHttpRequest\'s asynchronous response HTML document must not have a registry');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/share-registry-create-document.html b/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/share-registry-create-document.html
new file mode 100644
index 0000000..715aba8
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/share-registry-create-document.html
@@ -0,0 +1,52 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Document, created with createHTMLDocument or createDocument with HTML namespace, should share registry with the associated document</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="When DOMImplementation's createDocument method is invoked with namespace set to HTML Namespace or when the createHTMLDocument method is invoked, use the registry of the associated document to the new instance.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#creating-and-passing-registries">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var name = 'x-frame';
+
+    var GeneratedConstructor = doc.registerElement(name);
+    var doc2 = doc.implementation.createHTMLDocument('Document 2');
+    assert_throws(
+        'NotSupportedError',
+        function() { doc2.registerElement(name); },
+        'Registering a custom element type name that is already registered in a shared ' +
+            'registry should throw an exception');
+
+    var xframe = doc2.createElement(name);
+    assert_true(xframe instanceof GeneratedConstructor,
+        'Created element should be x-frame instance');
+}, 'Document created by createHTMLDocument should share an existing registry');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var name = 'x-frame-1';
+
+    var GeneratedConstructor = doc.registerElement(name);
+    var doc2 = doc.implementation.createDocument(HTML_NAMESPACE, 'html', null);
+    assert_throws(
+        'NotSupportedError',
+        function() { doc2.registerElement(name); },
+        'Exception should be thrown for custom element, ' +
+            'which is already registered in shared registry');
+
+    var xframe = doc2.createElement(name);
+    assert_true(xframe instanceof GeneratedConstructor,
+        'Created element should be x-frame instance');
+}, 'Document created by createDocument with HTML namespace should share an existing registry');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/share-registry-import-document.html b/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/share-registry-import-document.html
new file mode 100644
index 0000000..24c8468
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/creating-and-passing-registries/share-registry-import-document.html
@@ -0,0 +1,96 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>When creating an import, use the registry of the master document</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="When creating an import, use the registry of the master document.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#creating-and-passing-registries">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+var test1 = async_test('Registry of the imported document should be shared with master document. ' +
+    'Import is asynchronous');
+test1.step(function() {
+    var iframe = newIFrame('../resources/import-master-async.html');
+    document.body.appendChild(iframe);
+    iframe.onload = test1.step_func(function() {
+        var doc = iframe.contentDocument;
+        var link = doc.querySelector('link[rel=import]');
+        link.onload = test1.step_func(function() {
+            try {
+                var doc2 = link.import;
+                var name = 'x-frame';
+                doc.registerElement(name);
+                assert_throws(
+                    'NotSupportedError',
+                    function() { doc2.registerElement(name); },
+                    'Registering a custom element type name that is already registered in a shared ' +
+                        'registry should throw an exception');
+                test1.done();
+            } finally {
+                iframe.remove();
+            }
+        });
+    });
+});
+
+
+var test2 = async_test('Registry of the master document should be shared with imported document. ' +
+    'Import is asynchronous');
+test2.step(function() {
+    var iframe = newIFrame('../resources/import-master-async.html');
+    document.body.appendChild(iframe);
+    iframe.onload = test2.step_func(function() {
+        var doc = iframe.contentDocument;
+        var link = doc.querySelector('link[rel=import]');
+        link.onload = test2.step_func(function() {
+            try {
+                var doc2 = link.import;
+                var name = 'x-frame';
+                doc2.registerElement(name);
+                assert_throws(
+                    'NotSupportedError',
+                    function() { doc.registerElement(name); },
+                    'Registering a custom element type name that is already registered in a shared ' +
+                        'registry should throw an exception');
+                test2.done();
+            } finally {
+                iframe.remove();
+            }
+        });
+    });
+});
+
+
+testInIFrame('../resources/import-master.html', function(doc) {
+    var link = doc.querySelector('link[rel=import]');
+    var doc2 = link.import;
+    var name = 'x-frame';
+    doc.registerElement(name);
+    assert_throws(
+        'NotSupportedError',
+        function() { doc2.registerElement(name); },
+        'Registering a custom element type name that is already registered in a shared ' +
+            'registry should throw an exception');
+}, 'Registry of the imported document should be shared with master document. Import is syncronous');
+
+
+testInIFrame('../resources/import-master.html', function(doc) {
+    var link = doc.querySelector('link[rel=import]');
+    var doc2 = link.import;
+    var name = 'x-frame';
+    doc2.registerElement(name);
+    assert_throws(
+        'NotSupportedError',
+        function() { doc.registerElement(name); },
+        'Registering a custom element type name that is already registered in a shared ' +
+            'registry should throw an exception');
+}, 'Registry of the master document should be shared with imported document. Import is syncronous');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/enqueuing-and-invoking-callbacks/invoke-callbacks.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/enqueuing-and-invoking-callbacks/invoke-callbacks.html
new file mode 100644
index 0000000..7b72e67
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/enqueuing-and-invoking-callbacks/invoke-callbacks.html
@@ -0,0 +1,61 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Invoke CALLBACK with ELEMENT as callback this value</title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Invoke CALLBACK with ELEMENT as callback this value">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#enqueuing-and-invoking-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-a', {prototype: proto});
+    var customElement = new GeneratedConstructor();
+
+    doc.body.innerHTML = '<x-a id="x-a"></x-a>';
+    assert_equals(doc.querySelector('#x-a'), proto.createdCallbackThis,
+        '\'this\' value of the created callback should be the custom element');
+}, 'Test \'this\' value inside created callback.');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+
+    assert_equals(doc.querySelector('#x-element'), proto.attachedCallbackThis,
+        '\'this\' value of the attached callback should be the custom element');
+}, 'Test \'this\' value inside attached callback.');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+
+    var customElement = doc.querySelector('#x-element');
+    doc.body.removeChild(customElement);
+    assert_equals(customElement, proto.detachedCallbackThis,
+        '\'this\' value of the detached callback should be the custom element');
+}, 'Test \'this\' value inside detached callback.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-b', {prototype: proto});
+    var customElement = new GeneratedConstructor();
+
+    customElement.setAttribute('class', 'someClass');
+    assert_equals(customElement, proto.attributeChangedCallbackThis,
+        '\'this\' value of the attributeChanged callback should be the custom element');
+}, 'Test \'this\' value inside attributeChanged callback.');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attached-callback-move-element-test.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attached-callback-move-element-test.html
new file mode 100644
index 0000000..85b90d9
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attached-callback-move-element-test.html
@@ -0,0 +1,160 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Attached callback of a custom element should be called if element is moved</title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="attached callback ... must be enqueued whenever custom element is inserted into a document and this document has a browsing context.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-a', {prototype: proto});
+    var customElement = doc.createElement('x-a');
+
+    doc.body.appendChild(customElement);
+    assert_equals(proto.attachedCallbackCalledCounter, 0, 'Callback attached ' +
+        'should not be called in documents that do not have a browsing context');
+
+    var divElement = doc.createElement('div');
+    doc.body.appendChild(divElement);
+    divElement.appendChild(customElement);
+    assert_equals(proto.attachedCallbackCalledCounter, 0, 'Callback attached ' +
+        'should not be called in documents that do not have a browsing context');
+}, 'Test attached callback if moving custom element inside document ' +
+    'without browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(docWithBrowsingContext) {
+    var docNoBrowsingContext = newHTMLDocument();
+    var proto1 = newHTMLElementPrototype();
+    docNoBrowsingContext.registerElement('x-b', {prototype: proto1});
+
+    var customElement = docNoBrowsingContext.createElement('x-b');
+    docNoBrowsingContext.body.appendChild(customElement);
+    assert_equals(proto1.attachedCallbackCalledCounter, 0,
+        'Callback attached should not be called ' +
+        'in documents that do not have a browsing context');
+
+    var proto2 = newHTMLElementPrototype();
+    docWithBrowsingContext.registerElement('x-b', {prototype: proto2});
+    docWithBrowsingContext.body.appendChild(customElement);
+    assert_equals(proto1.attachedCallbackCalledCounter, 1,
+        'Callback attached should be called in documents with browsing context');
+    assert_equals(proto2.attachedCallbackCalledCounter, 0,
+        'Callback attached, defined in receiving document, should not be called');
+}, 'Test attached callback if moving custom element from ' +
+    'document without browsing context to document with browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(docWithBrowsingContext) {
+    var proto1 = newHTMLElementPrototype();
+    docWithBrowsingContext.registerElement('x-c', {prototype: proto1});
+
+    var customElement = docWithBrowsingContext.createElement('x-c');
+    docWithBrowsingContext.body.appendChild(customElement);
+    assert_equals(proto1.attachedCallbackCalledCounter, 1,
+        'Callback attached should be called in documents with browsing context');
+
+    var docNoBrowsingContext = newHTMLDocument();
+    var proto2 = newHTMLElementPrototype();
+    docNoBrowsingContext.registerElement('x-c', {prototype: proto2});
+    docNoBrowsingContext.body.appendChild(customElement);
+    assert_equals(proto1.attachedCallbackCalledCounter, 1, 'Callback attached should not be called ' +
+        'in documents that do not have a browsing context');
+    assert_equals(proto2.attachedCallbackCalledCounter, 0,
+        'Callback attached, defined in receiving document, should not be called');
+}, 'Test attached callback if moving custom element from ' +
+    'document with browsing context to document without browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-d', {prototype: proto});
+
+    var customElement = doc.createElement('x-d');
+    doc.body.appendChild(customElement);
+    assert_equals(proto.attachedCallbackCalledCounter, 1,
+        'Callback attached should be called in documents with browsing context');
+
+    var divElement = doc.createElement('div');
+    doc.body.appendChild(divElement);
+    divElement.appendChild(customElement);
+    assert_equals(proto.attachedCallbackCalledCounter, 2,
+        'Callback attached should be called in documents with browsing context');
+}, 'Test attached callback if moving custom element inside document ' +
+    'with browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-e', {prototype: proto});
+
+    var customElement = doc.createElement('x-e');
+    doc.body.appendChild(customElement);
+    assert_equals(proto.attachedCallbackCalledCounter, 1,
+        'Callback attached should be called in documents with browsing context');
+
+    var divElement = doc.createElement('div');
+    divElement.appendChild(customElement);
+    assert_equals(proto.attachedCallbackCalledCounter, 1,
+        'Callback attached should not be called if element is not appended to the document');
+
+    doc.body.appendChild(divElement);
+    assert_equals(proto.attachedCallbackCalledCounter, 2,
+        'Callback attached should be called in documents with browsing context');
+}, 'Test attached callback if indirectly moving custom element inside document ' +
+    'with browsing context');
+
+
+var moveTest =  async_test('Test attached callback if moving custom element from ' +
+    'document with browsing context to document with browsing context');
+
+moveTest.step(function() {
+    var iframe1 = newIFrame('../../resources/blank.html');
+    iframe1.onload = moveTest.step_func(function() {
+        var doc1 = iframe1.contentDocument;
+
+        // register custom element type
+        var proto1 = newHTMLElementPrototype();
+        doc1.registerElement('x-f', {prototype: proto1});
+
+        // create custom element
+        var customElement = doc1.createElement('x-f');
+        doc1.body.appendChild(customElement);
+        assert_equals(proto1.attachedCallbackCalledCounter, 1,
+            'Callback attached should be called in documents with browsing context');
+
+        // create second iframe
+        var iframe2 = newIFrame('../../resources/x-element.html');
+        iframe2.onload = moveTest.step_func(function() {
+            var doc2 = iframe2.contentDocument;
+            
+            // register custom element type
+            var proto2 = newHTMLElementPrototype();
+            doc2.registerElement('x-f', {prototype: proto2});
+
+            // move element
+            doc2.body.appendChild(customElement);
+            assert_equals(proto1.attachedCallbackCalledCounter, 2,
+                'Callback attached should be called in documents with browsing context');
+            assert_equals(proto2.attachedCallbackCalledCounter, 0,
+                'Callback attached, defined in receiving document, should not be called');
+
+            // test clean up
+            iframe1.remove();
+            iframe2.remove();
+            moveTest.done();
+        });
+    });
+});
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attached-callback-test.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attached-callback-test.html
new file mode 100644
index 0000000..d96805e
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attached-callback-test.html
@@ -0,0 +1,117 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Attached callback of a custom element should be called </title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="attached callback ... must be enqueued whenever custom element is inserted into a document and this document has a browsing context.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-a', {prototype: proto});
+    var customElement = new GeneratedConstructor();
+    assert_equals(proto.attachedCallbackCalledCounter, 0, 'Callback attached ' +
+        'should not be called in documents that do not have a browsing context');
+}, 'Test attached callback if custom element is instantiated via constructor. ' +
+    'Document has no browsing context');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-b', {prototype: proto});
+    doc.body.innerHTML = '<x-b></x-b>';
+    assert_equals(proto.attachedCallbackCalledCounter, 0, 'Callback attached ' +
+        'should not be called in documents that do not have a browsing context');
+}, 'Test attached callback if custom element is created via innerHTML property. ' +
+    'Document has no browsing context');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-c></x-c>';
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-c', {prototype: proto});
+    assert_equals(proto.attachedCallbackCalledCounter, 0, 'Callback attached ' +
+        'should not be called in documents that do not have a browsing context');
+}, 'Test attached callback if custom element is created via innerHTML property before ' +
+    'registration. Document has no browsing context');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-d id="x-d"></x-d>';
+    var customElement = doc.querySelector('#x-d');
+
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-d', {prototype: proto});
+
+    customElement.constructor.prototype = proto;
+    assert_equals(proto.attachedCallbackCalledCounter, 0, 'Callback attached should ' +
+        'not be called for unregistered custom element in document without browsing context');
+}, 'Test attached callback if custom element is unregistered');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    assert_equals(proto.attachedCallbackCalledCounter, 1, 'Callback attached should be ' +
+        'called in documents with browsing context');
+}, 'Test attached callback. Document has browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+
+    var x = doc.createElement('x-element');
+    assert_equals(proto.attachedCallbackCalledCounter, 0, 'Callback attached should not ' +
+        'be called before element is added to document with browsing context');
+
+    doc.body.appendChild(x);
+    assert_equals(proto.attachedCallbackCalledCounter, 1, 'Callback attached should be called ' +
+        'in documents with browsing context');
+}, 'Test attached callback. Registered element is created via document.createElement(). ' +
+    'Document has browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var x = doc.createElement('x-element');
+    doc.body.appendChild(x);
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    assert_equals(proto.attachedCallbackCalledCounter, 1, 'Callback attached should ' +
+        'be called in documents with browsing context');
+}, 'Test attached callback. Unregistered element is created via document.createElement(). ' +
+    'Document has browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    doc.body.innerHTML = '<x-element></x-element>';
+    assert_equals(proto.attachedCallbackCalledCounter, 1, 'Callback attached should ' +
+        'be called in documents with browsing context');
+}, 'Test attached callback. Registered element is created via innerHTML property. ' +
+    'Document has browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    doc.body.innerHTML = '<x-element></x-element>';
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    assert_equals(proto.attachedCallbackCalledCounter, 1, 'Callback attached should ' +
+        'be called in documents with browsing context');
+}, 'Test attached callback. Unresolved element is created via innerHTML property. ' +
+    'Document has browsing context');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attribute-changed-callback-change-attribute-test.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attribute-changed-callback-change-attribute-test.html
new file mode 100644
index 0000000..2b62070
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attribute-changed-callback-change-attribute-test.html
@@ -0,0 +1,230 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Test attributeChanged callback is called if custom element attribute value is changed</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="attributeChanged callback must be enqueued whenever custom element's attribute is added, changed or removed">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-a', {prototype: proto});
+    var customElement = new GeneratedConstructor();
+
+    customElement.setAttribute('class', 'someClass');
+    proto.attributeChangedCallbackCalledCounter = 0;
+    customElement.setAttribute('class', 'someClass2');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1,
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is called if attribute value is changed by method ' +
+    'setAttribute(). The custom element is created via constructor');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-b', {prototype: proto});
+
+    doc.body.innerHTML = '<x-b id="x-b" class="oldValue"></x-b>';
+    var customElement = doc.querySelector('#x-b');
+    customElement.setAttribute('class', 'newValue');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1,
+        'Callback attributeChanged should be called');
+    assert_array_equals(proto.attributeChangedCallbackArgs,
+        ['class', 'oldValue', 'newValue'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback arguments if attribute value is changed by method ' +
+    'setAttribute(). The custom element is created via innerHTML property');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-c', {prototype: proto});
+    var customElement = new GeneratedConstructor();
+
+    customElement.setAttribute('class', 'someClass');
+    proto.attributeChangedCallbackCalledCounter = 0;
+    customElement.classList.add('someClass3');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1,
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is called if attribute value is changed by method ' +
+    'classList.add(). The custom element is created via constructor');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-d', {prototype: proto});
+
+    doc.body.innerHTML = '<x-d id="x-d" class="oldValue"></x-d>';
+    var customElement = doc.querySelector('#x-d');
+    customElement.classList.add('newestValue');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1,
+        'Callback attributeChanged should be called');
+    assert_array_equals(proto.attributeChangedCallbackArgs,
+        ['class', 'oldValue', 'oldValue newestValue'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback arguments if attribute value is changed by method ' +
+    'classList.add(). The custom element is created via innerHTML property');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-e', {prototype: proto});
+    var customElement = new GeneratedConstructor();
+
+    customElement.setAttribute('class', 'someClass');
+    proto.attributeChangedCallbackCalledCounter = 0;
+    customElement.id = 'someId';
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1,
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is called if attribute value is changed as property. ' +
+    'The custom element is created via constructor');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-f', {prototype: proto});
+
+    doc.body.innerHTML = '<x-f id="x-f" class="oldValue"></x-f>';
+    var customElement = doc.querySelector('#x-f');
+    customElement.className = 'lastValue';
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1,
+        'Callback attributeChanged should be called');
+    assert_array_equals(proto.attributeChangedCallbackArgs,
+        ['class', 'oldValue', 'lastValue'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback arguments if attribute value is changed as property. ' +
+    'The custom element is created via innerHTML property');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-g', {prototype: proto});
+    var customElement = new GeneratedConstructor();
+
+    customElement.setAttribute('class', 'someClass someSuperClass');
+    proto.attributeChangedCallbackCalledCounter = 0;
+    customElement.classList.toggle('someClass');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1,
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is called if attribute value is changed by classList.toggle(). ' +
+    'The custom element is created via constructor');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-h', {prototype: proto});
+
+    doc.body.innerHTML = '<x-h id="x-h" class="oldValue lastValue"></x-h>';
+    var customElement = doc.querySelector('#x-h');
+    customElement.classList.toggle('lastValue');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1,
+        'Callback attributeChanged should be called');
+    assert_array_equals(proto.attributeChangedCallbackArgs,
+        ['class', 'oldValue lastValue', 'oldValue'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback arguments if attribute value is changed by classList.toggle(). ' +
+    'The custom element is created via innerHTML property');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-i id="x-i" class="oldValue"></x-i>';
+    var customElement = doc.querySelector('#x-i');
+    customElement.setAttribute('class', 'newValue');
+    customElement.setAttribute('class', 'newestValue');
+
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-i', {prototype: proto});
+
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 0,
+        'Callback attributeChanged should not be called');
+
+    customElement.setAttribute('class', 'rightValue');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1,
+        'Callback attributeChanged should not be called');
+    assert_array_equals(proto.attributeChangedCallbackArgs,
+        ['class', 'newestValue', 'rightValue'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback is not called if custom element is not registered');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+
+    var customElement = doc.querySelector('#x-element');
+    customElement.setAttribute('class', 'firstValue');
+    customElement.setAttribute('class', 'secondValue');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 2, 'Callback ' +
+        'attributeChanged should be called after call to setAttribute()');
+
+    customElement.classList.add('someClass3');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 3, 'Callback ' +
+        'attributeChanged should be called after call to classList.add()');
+
+    customElement.id = 'someId';
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 4, 'Callback ' +
+        'attributeChanged should be called after changing attribute as property');
+}, 'Test attributeChanged callback is called if attribute value is changed. ' +
+    'The document has browsing context');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    var customElement = doc.querySelector('#x-element');
+
+    customElement.setAttribute('class', 'firstValue');
+    customElement.setAttribute('class', 'secondValue');
+    assert_array_equals(proto.attributeChangedCallbackArgs,
+        ['class', 'firstValue', 'secondValue'],
+        'Unexpected callback attributeChanged arguments after call to setAttribute()');
+
+    customElement.classList.add('newestValue');
+    assert_array_equals(proto.attributeChangedCallbackArgs,
+        ['class', 'secondValue', 'secondValue newestValue'],
+        'Unexpected callback attributeChanged arguments after call to classList.add()');
+
+    customElement.className = 'lastValue';
+    assert_array_equals(proto.attributeChangedCallbackArgs,
+        ['class', 'secondValue newestValue', 'lastValue'],
+        'Unexpected callback attributeChanged arguments after changing attribute as property');
+}, 'Test attributeChanged callback arguments if attribute value is changed. ' +
+    'The document has browsing context');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var customElement = doc.querySelector('#x-element');
+    customElement.setAttribute('class', 'firstValue');
+    customElement.setAttribute('class', 'secondValue');
+
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    customElement.setAttribute('class', 'thirdValue');
+
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1,
+        'Callback attributeChanged should be called');
+    assert_array_equals(proto.attributeChangedCallbackArgs,
+        ['class', 'secondValue', 'thirdValue'],
+        'Unexpected callback attributeChanged arguments after setAttribute() call');
+}, 'Test attributeChanged callback is not called if custom element is not registered. ' +
+    'The document has browsing context');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attribute-changed-callback-remove-attribute-test.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attribute-changed-callback-remove-attribute-test.html
new file mode 100644
index 0000000..30e892c
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attribute-changed-callback-remove-attribute-test.html
@@ -0,0 +1,167 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Test attribute removing to check attributeChanged callback of a custom element</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="attributeChanged callback must be enqueued whenever custom element's attribute is removed">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-a', {prototype: proto});
+
+    var customElement = new GeneratedConstructor();
+    //attributeChangedCallback should be called the first time here
+    customElement.setAttribute('class', 'someClass');
+    //attributeChangedCallback should be called the second time here
+    customElement.removeAttribute('class');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 2, 'Callback attributeChanged should be called ' +
+        'after setAttribute() and removeAttribute() calls');
+}, 'Test attributeChanged callback if attribute is removed. ' +
+    'The custom element created via constructor');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(element) {
+        var obj = doc.createElement(element);
+        var proto = newCustomElementPrototype(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement('x-' + element + '-' + element + '-1', {
+            prototype: proto,
+            extends: element
+        });
+
+        var customElement = new GeneratedConstructor();
+        //attributeChangedCallback should be called the first time here
+        customElement.setAttribute('class', 'someClass');
+        //attributeChangedCallback should be called the second time here
+        customElement.removeAttribute('class');
+        assert_equals(proto.attributeChangedCallbackCalledCounter, 2, 
+            'Callback attributeChanged should be called ' +
+            'after setAttribute() and removeAttribute() calls for "' + element + '"');
+    });
+}, 'Test attributeChanged callback if attribute is removed. ' +
+    'The custom element created via constructor and extends HTML element');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-b', {prototype: proto});
+
+    doc.body.innerHTML = '<x-b id="x-b" class="theClass"></x-b>';
+    var customElement = doc.querySelector('#x-b');
+    customElement.removeAttribute('class');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+        'Callback attributeChanged should be called ' +
+        'after removeAttribute() call');
+}, 'Test attributeChanged callback if attribute is removed. ' +
+    'The custom element created via innerHTML property');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-c', {prototype: proto});
+
+    doc.body.innerHTML = '<x-c id="x-c" class="theClass"></x-c>';
+    var customElement = doc.querySelector('#x-c');
+    customElement.removeAttribute('class');
+    assert_equals(proto.attributeChangedCallbackArgs[2], null, 
+        'Removing an attribute should invoke ' +
+        'the attributeChanged callback with a null new value');
+    assert_array_equals(proto.attributeChangedCallbackArgs, 
+        ['class', 'theClass', null],
+        'Unexpected attributeChanged callback arguments');
+}, 'Test attributeChanged callback arguments if attribute is removed. ' +
+    'The custom element created via innerHTML property');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+
+    doc.body.innerHTML = '<x-d id="x-d" class="theClass"></x-d>';
+    var customElement = doc.querySelector('#x-d');
+    // this should not call or enqueue attributeChangedCallback
+    customElement.setAttribute('class', 'someClass');
+    // this one should not too
+    customElement.removeAttribute('class');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 0, 
+        'Callback attributeChanged should not be called');
+
+    doc.registerElement('x-d', {prototype: proto});
+    // this call invokes attributeChangedCallback
+    customElement.setAttribute('name', 'someName');
+    // and this one
+    customElement.removeAttribute('name');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 2, 
+        'Callback attributeChanged should be called ' +
+        'after setAttribute() and removeAttribute() calls');
+}, 'Test attributeChanged callback is not called if attribute is removed. ' +
+    'The custom element created via innerHTML property and unresolved at first');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+
+    var customElement = doc.querySelector('#x-element');
+    customElement.setAttribute('class', 'someClass');
+    customElement.removeAttribute('class');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 2, 
+        'Callback attributeChanged should be called ' +
+        'after setAttribute() and removeAttribute() calls');
+}, 'Test attributeChanged callback is called if attribute is removed. ' +
+    'The custom element created via constructor and the document has browsing context');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+
+    doc.body.innerHTML = '<x-element id="x-element" class="theClass"></x-element>';
+    var customElement = doc.querySelector('#x-element');
+    customElement.removeAttribute('class');
+    assert_equals(proto.attributeChangedCallbackArgs[2], null, 
+        'Removing an attribute should invoke ' +
+        'the attributeChanged callback with a null new value');
+    assert_array_equals(proto.attributeChangedCallbackArgs, 
+        ['class', 'theClass', null],
+        'Unexpected attributeChanged callback arguments');
+}, 'Test attributeChanged callback arguments if attribute is removed. ' +
+    'The custom element created via innerHTML property and the document has browsing context');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var customElement = doc.querySelector('#x-element');
+    // this should not call or enqueue attributeChangedCallback
+    customElement.setAttribute('name', 'someName');
+    // this one too
+    customElement.removeAttribute('name');
+
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 0, 
+        'Callback attributeChanged should not be called');
+    // this call invokes attributeChangedCallback
+    customElement.setAttribute('class', 'someClass');
+    // this call invokes attributeChangedCallback at second time
+    customElement.removeAttribute('class');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 2, 
+        'Callback attributeChanged should be called ' +
+        'after setAttribute() and removeAttribute() calls');
+}, 'Test attributeChanged callback if attribute is removed. ' +
+    'The custom element created via innerHTML property and unresolved at first. ' +
+    'The document has browsing context');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attribute-changed-callback-set-attribute-test.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attribute-changed-callback-set-attribute-test.html
new file mode 100644
index 0000000..cf15e12
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/attribute-changed-callback-set-attribute-test.html
@@ -0,0 +1,339 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Test attributeChanged callback is called if custom element attribute value is set</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="attributeChanged callback ... must be enqueued whenever custom element's attribute is added, changed or removed.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-a', {prototype: proto});
+
+    var customElement = new GeneratedConstructor();
+    customElement.setAttribute('class', 'someClass');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is called if attribute value is set by method ' +
+    'setAttribute(). The custom element is created via constructor.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-b', {prototype: proto});
+
+    var customElement = new GeneratedConstructor();
+    customElement.setAttribute('class', 'someClass');
+    assert_array_equals(proto.attributeChangedCallbackArgs, ['class', null, 'someClass'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback arguments if attribute value is set by method ' +
+    'setAttribute(). The custom element is created via constructor.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-c', {prototype: proto});
+
+    var customElement = new GeneratedConstructor();
+    customElement.classList.add('someClass');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is called if attribute value is set by method ' +
+    'classList.add(). The custom element is created via constructor.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-d', {prototype: proto});
+
+    var customElement = new GeneratedConstructor();
+    customElement.classList.add('someClass');
+    assert_array_equals(proto.attributeChangedCallbackArgs, ['class', null, 'someClass'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback arguments if attribute value is set by method ' +
+    'classList.add(). The custom element is created via constructor.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-e', {prototype: proto});
+
+    var customElement = new GeneratedConstructor();
+    customElement.classList.toggle('someClass');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is called if attribute value is set by method ' +
+    'classList.toggle(). The custom element is created via constructor.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-f', {prototype: proto});
+
+    var customElement = new GeneratedConstructor();
+    customElement.classList.toggle('someClass');
+    assert_array_equals(proto.attributeChangedCallbackArgs, ['class', null, 'someClass'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback arguments if attribute value is set by method ' +
+    'classList.toggle(). The custom element is created via constructor.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-g', {prototype: proto});
+
+    var customElement = new GeneratedConstructor();
+    customElement.className = 'someClass';
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1,
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is called if attribute value is set as property. ' +
+    'The custom element is created via constructor.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-h', {prototype: proto});
+
+    var customElement = new GeneratedConstructor();
+    customElement.className = 'someClass';
+    assert_array_equals(proto.attributeChangedCallbackArgs, ['class', null, 'someClass'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback arguments if attribute value is set as property. '+
+    'The custom element is created via constructor.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-i', {prototype: proto});
+
+    doc.body.innerHTML = '<x-i id="x-i" class="theClass"></x-i>';
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 0, 
+        'Callback attributeChanged should not be called');
+}, 'Test attributeChanged callback is not called if attribute value is specified in HTML. '+
+    'The custom element is created via innerHTML property.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-j', {prototype: proto});
+
+    doc.body.innerHTML = '<x-j id="x-j" class="theClass"></x-j>';
+    var customElement = doc.querySelector('#x-j');
+    customElement.setAttribute('class', 'someClass');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is called if attribute value is set by method setAttribute(). '+
+    'The custom element is created via innerHTML property.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-k', {prototype: proto});
+
+    doc.body.innerHTML = '<x-k id="x-k"></x-k>';
+    var customElement = doc.querySelector('#x-k');
+    customElement.setAttribute('class', 'someClass');
+    assert_array_equals(proto.attributeChangedCallbackArgs, ['class', null, 'someClass'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback arguments if attribute value is set by method setAttribute(). '+
+    'The custom element is created via innerHTML property.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+
+    doc.body.innerHTML = '<x-l id="x-l"></x-l>';
+    var customElement = doc.querySelector('#x-l');
+    // this call shouldn't invoke or enqueue the callback
+    customElement.setAttribute('class', 'someClass');
+
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-l', {prototype: proto});
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 0, 
+        'Callback attributeChanged should not be called');
+    // this one should
+    customElement.setAttribute('class', 'someClass2');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is not called if attribute value of unresolved element '+
+    'is set by method setAttribute().');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(element) {
+        var obj = doc.createElement(element);
+        var proto = newCustomElementPrototype(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement('x-' + element + '-' + element + '-1', {
+            prototype: proto,
+            extends: element
+        });
+
+        var customElement = new GeneratedConstructor();
+        customElement.setAttribute('class', 'someClass');
+        assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+            'Callback attributeChanged should be called');
+    });
+}, 'Test attributeChanged callback of the custom element that extends some HTML element. ' +
+    'Test that the callback is called');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(element) {
+        var obj = doc.createElement(element);
+        var proto = newCustomElementPrototype(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement('x-' + element + '-' + element + '-1-1', {
+            prototype: proto,
+            extends: element
+        });
+
+        var customElement = new GeneratedConstructor();
+        customElement.classList.add('someClass');
+        assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+            'Callback attributeChanged should be called');
+    });
+}, 'Test attributeChanged callback is called if attribute is set by method classList.add(). '+
+    'The custom element extends some HTML element.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(element) {
+        var obj = doc.createElement(element);
+        var proto = newCustomElementPrototype(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement('x-' + element + '-' + element + '-2', {
+            prototype: proto,
+            extends: element
+        });
+
+        var customElement = new GeneratedConstructor();
+        customElement.setAttribute('class', 'someClass');
+        assert_array_equals(proto.attributeChangedCallbackArgs, ['class', null, 'someClass'],
+            'Unexpected callback attributeChanged arguments');
+    });
+}, 'Test attributeChanged callback arguments if attribute value is set by method setAttribute(). '+
+    'The custom element extends some HTML element.');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+
+    var customElement = doc.querySelector('#x-element');
+    customElement.setAttribute('class', 'someClass');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is called if attribute value is set by method setAttribute(). '+
+    'The document has browsing context.');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+
+    var customElement = doc.querySelector('#x-element');
+    customElement.setAttribute('class', 'someClass');
+    assert_array_equals(proto.attributeChangedCallbackArgs, ['class', null, 'someClass'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback arguments if attribute value is set by method setAttribute(). '+
+    'The document has browsing context.');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+
+    var customElement = doc.querySelector('#x-element');
+    customElement.classList.add('someClass');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is called if attribute value is set by method classList.add(). '+
+    'The document has browsing context.');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+
+    var customElement = doc.querySelector('#x-element');
+    customElement.classList.add('someClass');
+    assert_array_equals(proto.attributeChangedCallbackArgs, ['class', null, 'someClass'],
+        'Unexpected callback attributeChanged arguments');
+}, 'Test attributeChanged callback arguments if attribute value is set by method classList.add(). '+
+    'The document has browsing context.');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var customElement = doc.querySelector('#x-element');
+    // this call shouldn't invoke or enqueue the callback
+    customElement.setAttribute('name', 'someName');
+
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 0, 
+        'Callback attributeChanged should not be called');
+    // this one should
+    customElement.setAttribute('class', 'someClass');
+    assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+        'Callback attributeChanged should be called');
+}, 'Test attributeChanged callback is not called if attribute value of unresolved element '+
+    'is set by method setAttribute(). The document has browsing context.');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    HTML5_ELEMENTS.forEach(function(element) {
+        var obj = doc.createElement(element);
+        var proto = newCustomElementPrototype(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement('x-' + element + '-' + element + '-1', {
+            prototype: proto,
+            extends: element
+        });
+
+        var customElement = new GeneratedConstructor();
+        customElement.setAttribute('class', 'someClass');
+        assert_equals(proto.attributeChangedCallbackCalledCounter, 1, 
+            'Callback attributeChanged should be called');
+    });
+}, 'Test attributeChanged callback is called if attribute value is set by method setAttribute(). '+
+    'The document has browsing context. The custom element extends some HTML element.');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    HTML5_ELEMENTS.forEach(function(element) {
+        var obj = doc.createElement(element);
+        var proto = newCustomElementPrototype(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement('x-' + element + '-' + element + '-2', {
+            prototype: proto,
+            extends: element
+        });
+
+        var customElement = new GeneratedConstructor();
+        customElement.setAttribute('class', 'someClass');
+        assert_array_equals(proto.attributeChangedCallbackArgs, ['class', null, 'someClass'],
+            'Unexpected callback attributeChanged arguments');
+    });
+}, 'Test attributeChanged callback arguments if attribute value is set by method setAttribute(). '+
+    'The document has browsing context. The custom element extends some HTML element.');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/created-callback-element-prototype-test.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/created-callback-element-prototype-test.html
new file mode 100644
index 0000000..a7e6294
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/created-callback-element-prototype-test.html
@@ -0,0 +1,88 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>The custom element prototype must be set just prior to invoking created callback</title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="The custom element prototype must be set just prior to invoking callback.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+
+    doc.body.innerHTML = '<x-a></x-a>';
+    doc.registerElement('x-a', {prototype: proto});
+    assert_equals(proto.createdCallbackThis.constructor.prototype, proto,
+        'The custom element prototype is incorrect inside created callback');
+}, 'Test custom element prototype inside created callback when custom element is created ' +
+    'in HTML before registration of a custom element');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+
+    doc.registerElement('x-b', {prototype: proto});
+    doc.body.innerHTML = '<x-b></x-b>';
+    assert_equals(proto.createdCallbackThis.constructor.prototype, proto,
+        'The custom element prototype is incorrect inside created callback');
+}, 'Test custom element prototype inside created callback when custom element is created ' +
+    'in HTML after registration of a custom element');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var customElement = doc.createElement('x-c');
+
+    doc.body.appendChild(customElement);
+    doc.registerElement('x-c', {prototype: proto});
+    assert_equals(proto.createdCallbackThis.constructor.prototype, proto,
+        'The custom element prototype is incorrect inside created callback');
+}, 'Test custom element prototype inside created callback when custom element is created ' +
+    'via document.createElement() before registration of a custom element');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-d', {prototype: proto});
+
+    var customElement = doc.createElement('x-d');
+    doc.body.appendChild(customElement);
+    assert_equals(proto.createdCallbackThis.constructor.prototype, proto,
+        'The custom element prototype is incorrect inside created callback');
+}, 'Test custom element prototype inside created callback when custom element is created ' +
+    'via document.createElement() after registration of a custom element');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-e', {prototype: proto});
+    var customElement = new GeneratedConstructor();
+
+    assert_equals(proto.createdCallbackThis.constructor.prototype, proto,
+        'The custom element prototype is incorrect inside created callback');
+}, 'Test custom element prototype inside created callback when custom element is created ' +
+    'via constructor returned by method registerElement');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    assert_equals(proto.createdCallbackThis.constructor.prototype, proto,
+        'The custom element prototype is incorrect inside created callback');
+}, 'Test custom element prototype inside created callback when custom element is created ' +
+    'by UA parser before registration of a custom element');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/created-callback-invocation-order-test.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/created-callback-invocation-order-test.html
new file mode 100644
index 0000000..e617ecd
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/created-callback-invocation-order-test.html
@@ -0,0 +1,243 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>All other callbacks must not be enqueued until after the created callback's invocation had started</title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="All other callbacks must not be enqueued until after the created callback's invocation had started.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+function newPrototypeWithCallbackLog() {
+    var proto = Object.create(HTMLElement.prototype);
+    proto.callbackLog = [];
+    proto.createdCallback = function() {
+        proto.callbackLog.push('created');
+    };
+    proto.attachedCallback = function() {
+        proto.callbackLog.push('attached');
+    };
+    proto.attributeChangedCallback = function() {
+        proto.callbackLog.push('attributeChanged');
+    };
+    proto.detachedCallback = function() {
+        proto.callbackLog.push('detached');
+    };
+    return proto;
+}
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var proto = newPrototypeWithCallbackLog();
+    doc.registerElement('x-a', {prototype: proto});
+    doc.body.innerHTML = '<x-a></x-a>';
+
+    assert_equals(proto.callbackLog[0], 'created', 'The callback ' +
+        proto.callbackLog[0] + ' should be enqueued after created callback');
+    assert_in_array('attached', proto.callbackLog, 'The callback ' +
+        'attached should be called');
+}, 'Test attached callback is enqueued after created callback');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var proto = newPrototypeWithCallbackLog();
+    doc.registerElement('x-b', {prototype: proto});
+    doc.body.innerHTML = '<x-b id="x-b"></x-b>';
+    var customElement = doc.querySelector('#x-b');
+    customElement.setAttribute('key', 'value');
+
+    assert_equals(proto.callbackLog[0], 'created', 'The callback ' +
+        proto.callbackLog[0] + ' should not be enqueued before created callback');
+    assert_in_array('attributeChanged', proto.callbackLog,
+        'The callback attributeChanged should be called');
+}, 'Test attributeChanged callback is enqueued after created callback. ' +
+    'Document has browsing context');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newPrototypeWithCallbackLog();
+    doc.registerElement('x-c', {prototype: proto});
+    doc.body.innerHTML = '<x-c id="x-c"></x-c>';
+    var customElement = doc.querySelector('#x-c');
+    customElement.setAttribute('key', 'value');
+    assert_equals(proto.callbackLog[0], 'created', 'The callback ' +
+        proto.callbackLog[0] + ' should not be enqueued before created callback');
+    assert_in_array('attributeChanged', proto.callbackLog,
+        'The callback attributeChanged should be called');
+}, 'Test attributeChanged callback is enqueued after created callback. ' +
+    'Document has no browsing context');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newPrototypeWithCallbackLog();
+    doc.registerElement('x-element', {prototype: proto});
+    var customElement = doc.querySelector('#x-element');
+    doc.body.removeChild(customElement);
+
+    assert_equals(proto.callbackLog[0], 'created', 'The callback ' +
+        proto.callbackLog[0] + ' should not be enqueued before created callback');
+    assert_in_array('detached', proto.callbackLog,
+        'The callback detached should be called');
+}, 'Test detached callback is enqueued after created callback.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto1 = newPrototypeWithCallbackLog();
+    proto1.createdCallback = function() {
+        proto1.callbackLog.push('created');
+        var xe = doc.querySelector('#x-e');
+        xe.setAttribute('key', 'value');
+    };
+    var proto2 = newPrototypeWithCallbackLog();
+
+    doc.registerElement('x-d', {prototype: proto1});
+    doc.registerElement('x-e', {prototype: proto2});
+    doc.body.innerHTML = '<x-d><x-e id="x-e"></x-e></x-d>';
+
+    assert_array_equals(proto2.callbackLog, ['created'],
+        'attributeChanged callback should not be enqueued before created callback');
+}, 'Test attributeChanged callback is not enqueued before created callback started. ' +
+    'Document has no browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var proto1 = newPrototypeWithCallbackLog();
+    proto1.createdCallback = function() {
+        proto1.callbackLog.push('created');
+        var xe = doc.querySelector('#x-g');
+        xe.setAttribute('key', 'value');
+    };
+    var proto2 = newPrototypeWithCallbackLog();
+
+    doc.registerElement('x-f', {prototype: proto1});
+    doc.registerElement('x-g', {prototype: proto2});
+    doc.body.innerHTML = '<x-f><x-g id="x-g"></x-g></x-f>';
+
+    assert_array_equals(proto2.callbackLog, ['created', 'attached'],
+        'attributeChanged callback should not be called before created callback started');
+}, 'Test attributeChanged callback is not enqueued before created callback started. ' +
+    'Document has browsing context');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newPrototypeWithCallbackLog();
+    proto.createdCallback = function() {
+        proto.callbackLog.push('created');
+        this.setAttribute('key', 'value');
+    };
+    doc.registerElement('x-h', {prototype: proto});
+    doc.body.innerHTML = '<x-h></x-h>';
+
+    assert_array_equals(proto.callbackLog, ['created', 'attributeChanged'],
+        'attributeChanged callback should be enqueued after created callback');
+}, 'Test attributeChanged callback is enqueued after created callback started. ' +
+    'Document has no browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(docWithBrowsingContext) {
+    var docNoBrowsingContext = newHTMLDocument();
+
+    var proto1 = newPrototypeWithCallbackLog();
+    var proto2 = newPrototypeWithCallbackLog();
+    proto1.createdCallback = function() {
+        proto1.callbackLog.push('created');
+        var xk = docNoBrowsingContext.querySelector('#x-k');
+        assert_equals(proto2.callbackLog.length, 0, 'Created callback for x-k ' +
+            'should not be called before created callback for x-i');
+        docWithBrowsingContext.body.appendChild(xk);
+    };
+
+    docNoBrowsingContext.registerElement('x-i', {prototype: proto1});
+    docNoBrowsingContext.registerElement('x-k', {prototype: proto2});
+    docNoBrowsingContext.body.innerHTML = '<x-i><x-k id="x-k"></x-k></x-i>';
+
+    // Though at the moment of inserting <x-k> into docWithBrowsingContext
+    // created callback is not called for <x-k> yet, attached calback is enqueued
+    // anyway. Because specification for setting custom element prototype algorithm reads:
+    //  ....
+    //   3. If ELEMENT is in a document and this document has a browsing context:
+    //       1. Enqueue attached callback for ELEMENT
+    //
+    // Changes in the specification will follow, to reflect this exceptional case.
+    assert_array_equals(proto2.callbackLog, ['created', 'attached'],
+        'attached callback should be enqueued when custom element prototype is set');
+}, 'Test attached callback is enqueued after created callback, but before created callback had started');
+
+
+testInIFrame('../../resources/blank.html', function(docWithBrowsingContext) {
+    var docNoBrowsingContext = newHTMLDocument();
+
+    var proto = newPrototypeWithCallbackLog();
+    proto.createdCallback = function() {
+        proto.callbackLog.push('created');
+        docWithBrowsingContext.body.appendChild(this);
+    };
+
+    docNoBrowsingContext.registerElement('x-l', {prototype: proto});
+    docNoBrowsingContext.body.innerHTML = '<x-l></x-l>';
+    assert_array_equals(proto.callbackLog, ['created', 'attached'],
+        'attached callback should be enqueued after created callback had started');
+}, 'Test attached callback is enqueued after created callback had started');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var proto1 = newPrototypeWithCallbackLog();
+    var proto2 = newPrototypeWithCallbackLog();
+    proto1.createdCallback = function() {
+        proto1.callbackLog.push('created');
+        var xn = doc.querySelector('#x-n');
+        assert_equals(proto2.callbackLog.length, 0, 'Created callback for x-n ' +
+            'should not be called before created callback for x-m');
+        this.removeChild(xn);
+    };
+
+    doc.registerElement('x-m', {prototype: proto1});
+    doc.registerElement('x-n', {prototype: proto2});
+    doc.body.innerHTML = '<x-m><x-n id="x-n"></x-n></x-m>';
+    assert_array_equals(proto2.callbackLog, ['created'],
+        'detached callback should not be enqueued before created callback had started');
+}, 'Test detached callback is not enqueued before created callback had started');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var proto = newPrototypeWithCallbackLog();
+    proto.createdCallback = function() {
+        proto.callbackLog.push('created');
+        this.remove();
+    };
+
+    doc.registerElement('x-o', {prototype: proto});
+    doc.body.innerHTML = '<x-o></x-o>';
+
+    assert_array_equals(proto.callbackLog, ['created', 'attached', 'detached'],
+        'detached callback should be enqueued after created callback had started');
+}, 'Test detached callback is enqueued after created callback had started');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newPrototypeWithCallbackLog();
+    doc.registerElement('x-element', {prototype: proto});
+
+    // Though at the moment of inserting <x-element> into the document
+    // created callback is not called for <x-element> yet, attached calback is enqueued
+    // anyway. Because specification for setting custom element prototype algorithm reads:
+    //  ....
+    //   3. If ELEMENT is in a document and this document has a browsing context:
+    //       1. Enqueue attached callback for ELEMENT
+    //
+    // Changes in the specification will follow, to reflect this exceptional case.
+    assert_array_equals(proto.callbackLog, ['created', 'attached'],
+        'attached callback should be enqueued when custom element prototype is set');
+}, 'Test attached callback is enqueued after created callback after registration ' +
+    'of custom element type');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/created-callback-invocation-test.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/created-callback-invocation-test.html
new file mode 100644
index 0000000..32a68f0
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/created-callback-invocation-test.html
@@ -0,0 +1,168 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Created callback of a custom element should be invoked after custom element instance is created and its definition is registered</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="CREATED callback is invoked after custom element instance is created and its definition is registered">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-a', {prototype: proto});
+    assert_equals(proto.createdCallbackCalledCounter, 0,
+        'Callback created should not be called before element instance was created');
+    var customElement = new GeneratedConstructor();
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be called after element instance was created');
+}, 'Test created callback when custom element is created by constructor');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-b', {prototype: proto});
+    assert_equals(proto.createdCallbackCalledCounter, 0,
+        'Callback created should not be called before element instance was created');
+    doc.body.innerHTML = '<x-b></x-b>';
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be called after element instance was created');
+}, 'Test created callback when custom element is created in HTML');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-c', {prototype: proto});
+    assert_equals(proto.createdCallbackCalledCounter, 0,
+        'Callback created should not be called before element instance was created');
+    doc.body.innerHTML = '<div><x-c></x-c></div>';
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be called after element instance was created');
+}, 'Test created callback when custom element is created in HTML as descendant of ' +
+    'another element');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-d', {prototype: proto});
+    assert_equals(proto.createdCallbackCalledCounter, 0,
+        'Callback created should not be called before element instance was created');
+    var customElement = doc.createElement('x-d');
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be called after element instance was created');
+}, 'Test created callback when custom element is created by createElement');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+
+    doc.body.innerHTML = '<x-e></x-e>';
+    doc.registerElement('x-e', {prototype: proto});
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be called after element instance was created');
+}, 'Test created callback when custom element is created in HTML before ' +
+    'registration of a custom element');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-f', {prototype: proto});
+    doc.body.innerHTML = '<x-f-unresolved id="x-f-unresolved"></x-f-unresolved>';
+    assert_equals(proto.createdCallbackCalledCounter, 0,
+        'Callback created should not be called if custom element is unresolved');
+
+    var customElement = doc.querySelector('#x-f-unresolved');
+    customElement.constructor.prototype = proto;
+    assert_equals(proto.createdCallbackCalledCounter, 0,
+        'Created callback should not be called if custom element is unresolved');
+}, 'Test created callback if custom element is unresolved.');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    assert_equals(proto.createdCallbackCalledCounter, 1, 'Callback created should be called');
+}, 'Test created callback is called after custom element is created and registered. ' +
+    'Document has browsing context');
+
+
+testInIFrame('../../resources/register-and-create-custom-element.html', function(doc) {
+    assert_equals(doc.querySelector('#log').textContent, 'Created callback was called',
+        'Callback created should be called');
+}, 'Test created callback is called after custom element is registered and created. ' +
+    'Document has browsing context');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var customElement = doc.createElement('x-g');
+
+    doc.registerElement('x-g', {prototype: proto});
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be called after registration of custom element');
+}, 'Test created callback when custom element is created by createElement '+
+    'before registration of a custom element');
+
+
+test(function(){
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var GeneratedConstructor = doc.registerElement('x-h', {prototype: proto});
+
+    var customElement1 = new GeneratedConstructor();
+    assert_equals(proto.createdCallbackCalledCounter, 1, 'Callback created should be called');
+
+    var customElement2 = doc.createElement('x-h');
+    assert_equals(proto.createdCallbackCalledCounter, 2,
+        'Callback created should be called after element instance was created');
+
+    doc.body.innerHTML = '<x-h></x-h>';
+    assert_equals(proto.createdCallbackCalledCounter, 3,
+        'Callback created should be called after element instance was created');
+
+    doc.body.innerHTML = '<div><x-h></x-h></div>';
+    assert_equals(proto.createdCallbackCalledCounter, 4,
+        'Callback created should be called after element instance was created');
+}, 'Test created callback. Create several custom elements using different ways');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+
+    var GeneratedConstructor = doc.registerElement('x-element', {prototype: proto});
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be called for custom element in loaded document');
+
+    var customElement2 = new GeneratedConstructor();
+    assert_equals(proto.createdCallbackCalledCounter, 2,
+        'Callback created should be called after element instance was created');
+
+    var customElement3 = doc.createElement('x-element');
+    assert_equals(proto.createdCallbackCalledCounter, 3,
+        'Callback created should be called after element instance was created');
+
+    doc.body.innerHTML = '<x-element></x-element>';
+    assert_equals(proto.createdCallbackCalledCounter, 4,
+        'Callback created should be called after element instance was created');
+
+    doc.body.innerHTML = '<div><x-element></x-element></div>';
+    assert_equals(proto.createdCallbackCalledCounter, 5,
+        'Callback created should be called after element instance was created');
+}, 'Test created callback. Create several custom elements using different ways. ' +
+    'Document has browsing context');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/detached-callback-move-element-test.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/detached-callback-move-element-test.html
new file mode 100644
index 0000000..960c0ad
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/detached-callback-move-element-test.html
@@ -0,0 +1,131 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Test detached callback of a custom element when moving custom element between different documents</title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="detached callback ... must be enqueued whenever custom element is removed from the document and this document has a browsing context.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-a', {prototype: proto});
+
+    var customElement = doc.createElement('x-a');
+    doc.body.appendChild(customElement);
+
+    var divElement = doc.createElement('div');
+    doc.body.appendChild(divElement);
+    divElement.appendChild(customElement);
+
+    assert_equals(proto.detachedCallbackCalledCounter, 0,
+        'Callback detached should not be called in document without a browsing context');
+}, 'Test detached callback is not called if moving custom element inside document ' +
+    'without browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(docWithBrowsingContext) {
+    var docNoBrowsingContext = newHTMLDocument();
+    var proto1 = newHTMLElementPrototype();
+    docNoBrowsingContext.registerElement('x-b', {prototype: proto1});
+
+    var customElement = docNoBrowsingContext.createElement('x-b');
+    docNoBrowsingContext.body.appendChild(customElement);
+    var proto2 = newHTMLElementPrototype();
+    docWithBrowsingContext.registerElement('x-b', {prototype: proto2});
+    docWithBrowsingContext.body.appendChild(customElement);
+
+    assert_equals(proto1.detachedCallbackCalledCounter, 0,
+        'Callback detached should not be called in document without browsing context');
+    assert_equals(proto2.detachedCallbackCalledCounter, 0,
+        'Callback detached, defined in receiving document, should not be called');
+}, 'Test detached callback is not called if moving custom element from ' +
+    'document without browsing context to document with browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(docWithBrowsingContext) {
+    var proto1 = newHTMLElementPrototype();
+    docWithBrowsingContext.registerElement('x-c', {prototype: proto1});
+
+    var customElement = docWithBrowsingContext.createElement('x-c');
+    docWithBrowsingContext.body.appendChild(customElement);
+
+    var docNoBrowsingContext = newHTMLDocument();
+    var proto2 = newHTMLElementPrototype();
+    docNoBrowsingContext.registerElement('x-c', {prototype: proto2});
+    docNoBrowsingContext.body.appendChild(customElement);
+    assert_equals(proto1.detachedCallbackCalledCounter, 1,
+        'Callback detached should be called in documents with browsing context');
+    assert_equals(proto2.detachedCallbackCalledCounter, 0,
+        'Callback detached, defined in receiving document, should not be called');
+}, 'Test detached callback if moving custom element from ' +
+    'document with browsing context to document without browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-d', {prototype: proto});
+
+    var customElement = doc.createElement('x-d');
+    doc.body.appendChild(customElement);
+    var divElement = doc.createElement('div');
+    doc.body.appendChild(divElement);
+    divElement.appendChild(customElement);
+    assert_equals(proto.detachedCallbackCalledCounter, 1,
+        'Callback detached should be called in documents with browsing context');
+}, 'Test detached callback if moving custom element inside document ' +
+    'with browsing context');
+
+
+var moveTest =  async_test('Test detached callback if moving custom element from ' +
+    'document with browsing context to document with browsing context');
+
+moveTest.step(function() {
+    var iframe1 = newIFrame('../../resources/blank.html');
+    iframe1.onload = moveTest.step_func(function() {
+        var doc1 = iframe1.contentDocument;
+
+        // register custom element type
+        var proto1 = newHTMLElementPrototype();
+        doc1.registerElement('x-e', {prototype: proto1});
+
+        // create custom element
+        var customElement = doc1.createElement('x-e');
+        doc1.body.appendChild(customElement);
+        assert_equals(proto1.detachedCallbackCalledCounter, 0,
+            'Callback detached should not be called when element is created');
+
+        // create second iframe
+        var iframe2 = newIFrame('../../resources/x-element.html');
+        iframe2.onload = moveTest.step_func(function() {
+            var doc2 = iframe2.contentDocument;
+
+            // register custom element type
+            var proto2 = newHTMLElementPrototype();
+            doc2.registerElement('x-e', {prototype: proto2});
+
+            // move element
+            doc2.body.appendChild(customElement);
+            assert_equals(proto1.detachedCallbackCalledCounter, 1,
+                'Callback detached should be called in documents with browsing context');
+            assert_equals(proto2.detachedCallbackCalledCounter, 0,
+                'Callback detached, defined in receiving document, should not be called');
+
+            // test clean up
+            iframe1.remove();
+            iframe2.remove();
+            moveTest.done();
+        });
+
+    });
+});
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/detached-callback-no-browsing-context-test.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/detached-callback-no-browsing-context-test.html
new file mode 100644
index 0000000..fd401c8
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/detached-callback-no-browsing-context-test.html
@@ -0,0 +1,148 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Detached callback of a custom element should not be called if document has no browsing context</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="detached callback ... must be enqueued whenever custom element is removed from the document and this document has a browsing context.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-a', {prototype: proto});
+    doc.body.innerHTML = '<x-a id="x-a"></x-a>';
+    var customElement = doc.querySelector('#x-a');
+    doc.body.removeChild(customElement);
+
+    assert_equals(proto.detachedCallbackCalledCounter, 0,
+        'Callback detached should not be called if the document has no browsing context');
+}, 'Test detached callback if custom element is created via innerHTML property. ' +
+    'Document has no browsing context');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    doc.body.innerHTML = '<x-b id="x-b"></x-b>';
+    doc.registerElement('x-b', {prototype: proto});
+    var customElement = doc.querySelector('#x-b');
+    doc.body.removeChild(customElement);
+
+    assert_equals(proto.detachedCallbackCalledCounter, 0,
+        'Callback detached should not be called if the document has no browsing context');
+}, 'Test detached callback if custom element is via innerHTML property before ' +
+    'registration of a custom element. Document has no browsing context');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-c id="x-c"></x-c>';
+    var customElement = doc.querySelector('#x-c');
+
+    var proto = newHTMLElementPrototype();
+    customElement.constructor.prototype = proto;
+    doc.body.removeChild(customElement);
+
+    assert_equals(proto.detachedCallbackCalledCounter, 0,
+        'Callback detached should not be called if the document has no browsing context');
+}, 'Test detached callback if custom element is unregistered. ' +
+    'Document has no browsing context');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+
+    doc.registerElement('x-d', {prototype: proto});
+    doc.body.innerHTML = '<x-d id="x-d"></x-d>';
+    doc.body.innerHTML = '';
+
+    assert_equals(proto.detachedCallbackCalledCounter, 0,
+        'Callback detached should not be called if the document has no browsing context');
+}, 'Test detached callback if removing custom element via innerHTML property. ' +
+    'Document has no browsing context');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+
+    doc.registerElement('x-e', {prototype: proto});
+    doc.body.innerHTML = '<div id="customParent"><x-e id="x-e"></x-e></div>';
+    var parent = doc.querySelector('#customParent');
+    doc.body.removeChild(parent);
+
+    assert_equals(proto.detachedCallbackCalledCounter, 0,
+        'Callback detached should not be called if the document has no browsing context');
+}, 'Test detached callback if removing perent of custom element. ' +
+    'Document has no browsing context');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+
+    doc.registerElement('x-f', {prototype: proto});
+    doc.body.innerHTML = '<div><x-f id="x-f"></x-f></div>';
+    doc.body.innerHTML = '';
+
+    assert_equals(proto.detachedCallbackCalledCounter, 0,
+        'Callback detached should not be called if the document has no browsing context');
+}, 'Test detached callback if removing perent of custom element via innerHTML property. ' +
+    'Document has no browsing context');
+
+
+var loseBrowsingContextTest = async_test('Test detached callback is not called ' +
+    'if document lose browsing context and custom element is removed');
+
+loseBrowsingContextTest.step(function() {
+    var iframe = newIFrame('../../resources/x-element.html');
+    iframe.onload = loseBrowsingContextTest.step_func(function(){
+        var doc = iframe.contentDocument;
+        var proto = newHTMLElementPrototype();
+        doc.registerElement('x-element', {prototype: proto});
+
+        var customElement = doc.querySelector('#x-element');
+        iframe.remove();
+        customElement.remove();
+
+        assert_equals(proto.detachedCallbackCalledCounter, 0,
+            'Callback detached should not be called if the document has no browsing context');
+        loseBrowsingContextTest.done();
+    });
+});
+
+
+var navigateTest = async_test('Test detached callback is not called, ' +
+    'if document\'s window is navigated to another document and custom element is removed');
+
+navigateTest.step(function() {
+    var iframe = newIFrame('../../resources/x-element.html');
+    iframe.onload = navigateTest.step_func(function() {
+        var doc = iframe.contentDocument;
+        var proto = newHTMLElementPrototype();
+        doc.registerElement('x-element', {prototype: proto});
+        customElement = doc.querySelector('#x-element');
+
+        iframe.onload = navigateTest.step_func(function() {
+            customElement.remove();
+            assert_equals(proto.detachedCallbackCalledCounter, 0,
+                'Callback detached should not be called ' +
+                'if the document has no browsing context');
+            navigateTest.done();
+            iframe.remove();
+        });
+        iframe.src = '../../resources/blank.html';
+    });
+});
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/detached-callback-with-browsing-context-test.html b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/detached-callback-with-browsing-context-test.html
new file mode 100644
index 0000000..3f6681b
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/custom-element-lifecycle/types-of-callbacks/detached-callback-with-browsing-context-test.html
@@ -0,0 +1,86 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Detached callback of a custom element should be called if document has browsing context</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="detached callback ... must be enqueued whenever custom element is removed from the document and this document has a browsing context.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    var customElement = doc.querySelector('#x-element');
+    doc.body.removeChild(customElement);
+    assert_equals(proto.detachedCallbackCalledCounter, 1, 'Callback detached should be ' +
+        'called if custom element is removed from the document with browsing context');
+}, 'Test detached callback is called if custom element is removed by method removeChild() ' +
+    'from document with browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    doc.body.innerHTML = '<div id="x-a-parent"><x-a id="x-a"></x-a></div>';
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-a', {prototype: proto});
+    var div = doc.querySelector('#x-a-parent');
+    doc.body.removeChild(div);
+    assert_equals(proto.detachedCallbackCalledCounter, 1, 'Callback detached should be ' +
+        'called if custom element is removed from the document with browsing context');
+}, 'Test detached callback is called if ancestor node of custom element ' +
+    'is removed by method removeChild() from document with browsing context');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    var customElement = doc.querySelector('#x-element');
+    var div = doc.createElement('div');
+    doc.body.replaceChild(div, customElement);
+    assert_equals(proto.detachedCallbackCalledCounter, 1, 'Callback detached should be ' +
+        'called if custom element is removed from the document with browsing context');
+}, 'Test detached callback is called if custom element is removed by method replaceChild() ' +
+    'from document with browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-b', {prototype: proto});
+    doc.body.innerHTML = '<div id="x-b-parent"><x-b id="x-b"></x-b></div>';
+    var parent = doc.querySelector('#x-b-parent');
+    var replacement = doc.createElement('div');
+    doc.body.replaceChild(replacement, parent);
+    assert_equals(proto.detachedCallbackCalledCounter, 1, 'Callback detached should be ' +
+        'called if custom element is removed from the document with browsing context');
+}, 'Test detached callback is called if ancestor node of custom element ' +
+    'is removed by method replaceChild() from document with browsing context');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-element', {prototype: proto});
+    doc.body.innerHTML = '';
+    assert_equals(proto.detachedCallbackCalledCounter, 1, 'Callback detached should be ' +
+        'called if custom element is removed from the document with browsing context');
+}, 'Test detached callback is called after changing custom element direct parent ' +
+    'innerHTML property in the document with browsing context');
+
+
+testInIFrame('../../resources/blank.html', function(doc) {
+    doc.body.innerHTML = '<div><x-c></x-c></div>';
+    var proto = newHTMLElementPrototype();
+    doc.registerElement('x-c', {prototype: proto});
+    doc.body.innerHTML = '';
+    assert_equals(proto.detachedCallbackCalledCounter, 1, 'Callback detached should be ' +
+        'called if custom element is removed from the document with browsing context');
+}, 'Test detached callback is called after changing custom element ancestor ' +
+    'innerHTML property in the document with browsing context');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/changing-is-attribute.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/changing-is-attribute.html
new file mode 100644
index 0000000..91ab563
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/changing-is-attribute.html
@@ -0,0 +1,159 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Changing IS attribute of the custom element must not affect this element's custom element type, after element is instantiated</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="After a custom element is instantiated, changing the value of the IS attribute must not affect this element's custom element type">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-a');
+    var customElement = new GeneratedConstructor();
+    doc.registerElement('x-b');
+    customElement.setAttribute('is', 'x-b');
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be x-a');
+}, 'Test custom element type, after assigning IS attribute value. ' +
+    'Element is created by constructor');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-c');
+    doc.registerElement('x-d');
+    doc.body.innerHTML = '<x-c id="x-c"></x-c>';
+    var customElement = doc.querySelector('#x-c');
+    customElement.setAttribute('is', 'x-d');
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be x-c');
+}, 'Test custom element type, after assigning IS attribute value. ' +
+    'Element is created via innerHTML property');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-e id="x-e"></x-e>';
+    var customElement = doc.querySelector('#x-e');
+    customElement.setAttribute('is', 'x-f');
+    var GeneratedConstructor = doc.registerElement('x-e');
+    doc.registerElement('x-f');
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be x-e');
+}, 'Test custom element type, after assigning IS attribute value to unresolved element. ' +
+    'Element is created via innerHTML property');
+
+
+testInIFrame('../resources/x-element.html', function(doc) {
+    var GeneratedConstructor = doc.registerElement('x-element');
+    doc.registerElement('y-element');
+    var customElement = doc.querySelector('#x-element');
+    customElement.setAttribute('is', 'y-element');
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be x-element');
+}, 'Test custom element type, after assigning IS attribute value. ' +
+    'Element is defined in loaded HTML document');
+
+
+testInIFrame('../resources/x-element.html', function(doc) {
+    var customElement = doc.querySelector('#x-element');
+    customElement.setAttribute('is', 'y-element');
+    var GeneratedConstructor = doc.registerElement('x-element');
+    doc.registerElement('y-element');
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be x-element');
+}, 'Test custom element type, after assigning IS attribute value to unresolved element. ' +
+    'Element is defined in loaded HTML document');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        if (HTML5_DOCUMENT_ELEMENTS.indexOf(tagName) !== -1) {
+            return;
+        }
+        var name = 'y-' + tagName;
+        var obj = doc.createElement(tagName);
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {prototype: proto, extends: tagName});
+        if (HTML5_TABLE_ELEMENTS.indexOf(tagName) !== -1) {
+            doc.body.innerHTML =
+                '<table>' +
+                '<' + tagName + ' id="custom-element" is="' + name + '"></' + tagName + '>' +
+                '</table>';
+        } else {
+            doc.body.innerHTML =
+                '<' + tagName + ' id="custom-element" is="' + name + '"></' + tagName + '>';
+        }
+        var customElement = doc.querySelector('#custom-element');
+        assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+            'Custom element type should be '+ name);
+
+        var name2 = 'y-a-' + tagName;
+        doc.registerElement(name2);
+        customElement.setAttribute('is', name2);
+        assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+            'Custom element type should be ' + name);
+    });
+}, 'Test custom element type after changing IS attribute value. ' +
+    'Element is HTML5 element with IS attribute referring to custom element type');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var localName = 'z-a';
+    var obj = doc.createElement('a');
+    var proto = Object.create(obj.constructor.prototype);
+    var GeneratedConstructor = doc.registerElement(localName, {prototype: proto, extends: 'a'});
+    doc.body.innerHTML = '<a id="custom-element" is="' + localName + '"></a>';
+    var customElement = doc.querySelector('#custom-element');
+
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var name = 'z-a-' + tagName;
+        var htmlElement = doc.createElement(tagName);
+        var htmlElementProto = Object.create(htmlElement.constructor.prototype);
+        doc.registerElement(name, {prototype: htmlElementProto, extends: tagName});
+        customElement.setAttribute('is', name);
+        assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+            'Custom element type should be ' + localName);
+    });
+}, 'Test custom element type after changing IS attribute value several times. ' +
+    'Element is HTML5 element with IS attribute referring to custom element type');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-g');
+    doc.registerElement('x-h');
+    doc.body.innerHTML = '<x-g id="x-g" is="x-h"></x-g>';
+    var customElement = doc.querySelector('#x-g');
+    customElement.removeAttribute('is');
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be x-g');
+}, 'Test custom element type, after removing IS attribute value. ' +
+    'Element is created via innerHTML property');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var obj = doc.createElement('a');
+    var proto = Object.create(obj.constructor.prototype);
+    var GeneratedConstructor = doc.registerElement('x-i', {prototype: proto, extends: 'a'});
+    doc.body.innerHTML = '<a id="x-i" is="x-i"></a>';
+    var customElement = doc.querySelector('#x-i');
+    customElement.removeAttribute('is');
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be x-i');
+}, 'Test custom element type, after removing IS attribute value. ' +
+    'Element is HTML5 element with IS attribute referring to custom element type');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-is-attribute.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-is-attribute.html
new file mode 100644
index 0000000..aef9135
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-is-attribute.html
@@ -0,0 +1,50 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Custom element constructor sets value of IS attribute to custom element type, if it is not equal to name</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If TYPE is not the same as NAME, set the value of ELEMENT's IS attribute to TYPE">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        if (HTML5_DOCUMENT_ELEMENTS.indexOf(tagName) !== -1) {
+            return;
+        }
+        var obj = doc.createElement(tagName);
+        var name = 'x-a-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {prototype: proto, extends: tagName});
+        var customElement = new GeneratedConstructor();
+
+        assert_equals(customElement.getAttribute('is'), name,
+            'Value of the IS attribute should be set to type');
+    });
+}, 'Test that the constructor of a type extension sets the IS attribute value to the type');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        if (HTML5_DOCUMENT_ELEMENTS.indexOf(tagName) !== -1) {
+            return;
+        }
+        var name = 'x-b-' + tagName;
+        var GeneratedConstructor = doc.registerElement(name);
+        var customElement = new GeneratedConstructor();
+
+        assert_false(customElement.hasAttribute('is'),
+            'IS attribute should not present if local name is the same as type');
+    });
+}, 'Test that the constructor of a custom element does not set the IS attribute if local name is the same as type');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-local-name.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-local-name.html
new file mode 100644
index 0000000..6929c36
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-local-name.html
@@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Custom element constructor sets local name to the name from custom element definition</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="Set ELEMENT's local name to NAME">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-a');
+    var customElement = new GeneratedConstructor();
+    assert_equals(customElement.localName, 'x-a',
+        'Custom element local name should be equal to the name in custom element definition');
+}, 'Custom element constructor sets local name to the name from custom element definition');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-b-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {
+            prototype: proto,
+            extends: tagName
+        });
+        var customElement = new GeneratedConstructor();
+
+        assert_equals(customElement.localName, tagName,
+            'Custom element local name should be equal to the name in custom element definition');
+    });
+}, 'Custom element constructor sets local name to the name from custom element definition. ' +
+    'Test constructor of extended HTML element');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-namespace.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-namespace.html
new file mode 100644
index 0000000..c0de2b1
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-namespace.html
@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Custom element constructor sets local namespace to the namespace from custom element definition</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Custom element constructor sets custom element namespace to the namespace in custom element definition">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-a');
+    var customElement = new GeneratedConstructor();
+    assert_equals(customElement.namespaceURI, HTML_NAMESPACE,
+        'Custom element namespace should be equal to namespace in custom element definition');
+}, 'Custom element constructor sets namespace to the namespace from custom element definition');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-b-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {
+            prototype: proto,
+            extends: tagName
+        });
+        var customElement = new GeneratedConstructor();
+
+        assert_equals(customElement.namespaceURI, HTML_NAMESPACE,
+            'Custom element namespace should be equal to namespace in custom element definition');
+    });
+}, 'Custom element constructor sets namespace to the namespace from custom element definition. ' +
+    'Test constructor of extended HTML element');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-node-document.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-node-document.html
new file mode 100644
index 0000000..b56c1a0
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-node-document.html
@@ -0,0 +1,101 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Custom element constructor sets owner document to the document, where custom element type is registered</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Custom element constructor sets custom element node document to the document, where custom element type is registered">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-a');
+    var customElement = new GeneratedConstructor();
+    assert_equals(customElement.ownerDocument, doc,
+        'Custom element owner document should be the document, where custom element ' +
+        'type is registered');
+}, 'Custom element constructor sets owner document to the document, where custom element ' +
+    'type is registered');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-b-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {
+            prototype: proto,
+            extends: tagName
+        });
+        var customElement = new GeneratedConstructor();
+
+        assert_equals(customElement.ownerDocument, doc,
+            'Custom element owner document should be the document, where custom element ' +
+            'type is registered');
+    });
+}, 'Custom element constructor sets owner document to the document, where custom element ' +
+    'type is registered. Test constructor of extended HTML element');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var sharedRegistryDocument = doc.implementation.createHTMLDocument('Document 2');
+
+    var name = 'x-c';
+    var GeneratedConstructor = doc.registerElement(name);
+    var customElement = new GeneratedConstructor();
+    assert_equals(customElement.ownerDocument, doc,
+        'Custom element owner document should be the document, where custom element ' +
+        'type is registered');
+
+    var name2 = 'x-d';
+    var GeneratedConstructor2 = sharedRegistryDocument.registerElement(name2);
+    var customElement2 = new GeneratedConstructor2();
+    assert_equals(customElement2.ownerDocument, sharedRegistryDocument,
+        'Custom element owner document should be the document, where custom element ' +
+        'type is registered');
+}, 'Custom element constructor sets owner document to the document, where custom element ' +
+    'type is registered. Test different documents with shared registry');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var sharedRegistryDocument = doc.implementation.createHTMLDocument('Document 2');
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-e-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {
+            prototype: proto,
+            extends: tagName
+        });
+        var customElement = new GeneratedConstructor();
+        assert_equals(customElement.ownerDocument, doc,
+            'Custom element owner document should be the document, where custom element ' +
+            'type is registered');
+
+        var obj2 = sharedRegistryDocument.createElement(tagName);
+        var name2 = 'x-f-' + tagName;
+        var proto2 = Object.create(obj2.constructor.prototype);
+        var GeneratedConstructor2 = sharedRegistryDocument.registerElement(name2, {
+            prototype: proto2,
+            extends: tagName
+        });
+        var customElement2 = new GeneratedConstructor2();
+        assert_equals(customElement2.ownerDocument, sharedRegistryDocument,
+            'Custom element owner document should be the document, where custom element ' +
+            'type is registered');
+    });
+}, 'Custom element constructor sets owner document to the document, where custom element ' +
+    'type is registered. Test constructor of extended HTML element for different documents ' +
+    'with shared registry');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-prototype.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-prototype.html
new file mode 100644
index 0000000..f5e14d4
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-constructor-prototype.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Custom element constructor prototype is the prototype object specified in element definition</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Custom element constructor prototype is the prototype object specified in element definition">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = Object.create(SVGElement.prototype);
+    var GeneratedConstructor = doc.registerElement('x-a', {
+        prototype: proto,
+        extends: 'p'
+    });
+    assert_true(GeneratedConstructor.prototype === proto,
+        'Custom element constructor must have the prototype specified in registerElement()');
+}, 'If custom element type is registered with prototype, the custom element ' +
+   'constructor should have the prototype specified in registerElement() call');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-prototype.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-prototype.html
new file mode 100644
index 0000000..ab0fd85
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-prototype.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Custom element prototype is the prototype object specified in element definition</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Custom element prototype is the prototype object specified in element definition">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = Object.create(SVGElement.prototype);
+    var GeneratedConstructor = doc.registerElement('x-a', {
+        prototype: proto,
+        extends: 'p'
+    });
+    var customElement = new GeneratedConstructor();
+
+    assert_true(Object.getPrototypeOf(customElement) === proto,
+        'Custom element instance must have the prototype specified in registerElement()');
+}, 'If custom element type is registered with prototype, the custom element ' +
+    'instance should have the prototype specified in registerElement() call');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-type-is-attribute.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-type-is-attribute.html
new file mode 100644
index 0000000..e16d84c
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-type-is-attribute.html
@@ -0,0 +1,74 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Instantiation of custom element: custom element type is given as the value of the IS attribute</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="The custom element type is given to a custom element at the time of its instantation in one of the two ways: ... 2. As the value of the IS attribute of the custom element.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        if (HTML5_DOCUMENT_ELEMENTS.indexOf(tagName) !== -1) {
+            return;
+        }
+        var obj = doc.createElement(tagName);
+        var name = 'x-a-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {prototype: proto, extends: tagName});
+
+        if (HTML5_TABLE_ELEMENTS.indexOf(tagName) !== -1) {
+            doc.body.innerHTML =
+                '<table>' +
+                '<' + tagName + ' id="custom-element" is="' + name + '"></' + tagName + '>' +
+                '</table>';
+        } else {
+            doc.body.innerHTML =
+                '<' + tagName + ' id="custom-element" is="' + name + '"></' + tagName + '>';
+        }
+        var customElement = doc.querySelector('#custom-element');
+        assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+            'Custom element type should be the type, specified as value of IS attribute');
+    });
+}, 'Instantiation of custom element: custom element type is given as the value of ' +
+    'the IS attribute');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        if (HTML5_DOCUMENT_ELEMENTS.indexOf(tagName) !== -1) {
+            return;
+        }
+        var obj = doc.createElement(tagName);
+        var name = 'x-b-' + tagName;
+        if (HTML5_TABLE_ELEMENTS.indexOf(tagName) !== -1) {
+            doc.body.innerHTML =
+                '<table>' +
+                '<' + tagName + ' id="custom-element" is="' + name + '"></' + tagName + '>' +
+                '</table>';
+        } else {
+            doc.body.innerHTML =
+                '<' + tagName + ' id="custom-element" is="' + name + '"></' + tagName + '>';
+        }
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {prototype: proto, extends: tagName});
+
+        var customElement = doc.querySelector('#custom-element');
+
+        assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+            'Custom element type should be the type, specified as value of IS attribute');
+    });
+}, 'Instantiation of custom element: custom element type is given as the value ' +
+    'of the IS attribute. Custom element is unresolved at first');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-type-local-name-and-is-attribute.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-type-local-name-and-is-attribute.html
new file mode 100644
index 0000000..9751ec3
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-type-local-name-and-is-attribute.html
@@ -0,0 +1,102 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Instantiation of custom element: the custom tag must win over the type extension</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="If both types of custom element types are provided at the time of element's instantiation, the custom tag must win over the type extension">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-a');
+    doc.registerElement('x-b');
+    doc.body.innerHTML = '<x-a id="x-a" is="x-b"></x-a>';
+    var customElement = doc.querySelector('#x-a');
+
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be the type, specified in the local name of the element');
+}, 'Custom element type must be taken from the local name of the element even ' +
+    'if IS attribute provided.');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.registerElement('x-d');
+    doc.body.innerHTML = '<x-c id="x-c" is="x-d"></x-c>';
+    var customElement = doc.querySelector('#x-c');
+
+    var GeneratedConstructor = doc.registerElement('x-c');
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be the type, specified in the local name of the element');
+}, 'Custom element type must be taken from the local name of the element even ' +
+    'if IS attribute provided. Custom element is unresolved at first');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-f');
+    doc.body.innerHTML = '<x-f id="x-f" is="x-e"></x-f>';
+    var customElement = doc.querySelector('#x-f');
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be the type, specified in local name of the element');
+
+    doc.registerElement('x-e');
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be the type, specified in local name of the element');
+}, 'Custom element type must be taken from the local name of the element even if IS ' +
+    'attribute provided. There\'s no definition for the value of IS attribute at first');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-element');
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-d-' + tagName;
+        doc.registerElement(name, {
+            prototype: Object.create(obj.constructor.prototype),
+            extends: tagName
+        });
+        doc.body.innerHTML = '<x-element id="x-element" is="' + name + '"></x-element>';
+        var customElement = doc.querySelector('#x-element');
+        assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+            'Custom element type should be the local name of the custom element');
+    });
+}, 'Custom element type must be taken from the local name of the element even ' +
+    'if IS attribute provided. IS attribute refers to another custom element type, ' +
+    'which extends HTML5 elements');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.registerElement('y-element');
+
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-e-' + tagName;
+        var id = 'x-e-' + tagName;
+        doc.registerElement(name, {
+            prototype: Object.create(obj.constructor.prototype),
+            extends: tagName
+        });
+        doc.body.innerHTML = '<' + name + ' id="' + id + '" is="y-element"></' + name + '>';
+        var customElement = doc.querySelector('#' + id);
+        // We have <x-e-a is='y-element'>. Custom element type for this will be
+        // HTMLElement, not x-e-a (for x-e-a there should be <a is='x-e-a'>...)
+        assert_class_string(customElement, 'HTMLElement',
+            'Custom element type should be HTMLElement');
+    });
+}, 'Custom element type must be taken from the local name of the custom element even ' +
+    'if IS attribute provided. The element extends HTML5 elements, IS attribute refers ' +
+    'to another custom element type.');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-type-local-name.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-type-local-name.html
new file mode 100644
index 0000000..9687313
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/custom-element-type-local-name.html
@@ -0,0 +1,39 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Instantiation of custom element: custom element type is given via the local name of the custom element</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="The custom element type is given to a custom element at the time of its instantation in one of the two ways: 1. As the local name of the custom element.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-a');
+    doc.body.innerHTML = '<x-a id="x-a"></x-a>';
+    var customElement = doc.querySelector('#x-a');
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be the type, specified by the local name of ' +
+        'the custom element');
+}, 'Test custom element type, which is given via the local name of the custom element. ' +
+    'Custom element created via innerHTML property');
+
+
+testInIFrame('../resources/x-element.html', function(doc) {
+    var GeneratedConstructor = doc.registerElement('x-element');
+    var xelement = doc.querySelector('#x-element');
+    assert_equals(Object.getPrototypeOf(xelement), GeneratedConstructor.prototype,
+        'Custom element type should be the type, specified by the local name of ' +
+        'the custom element');
+}, 'Test custom element type, which is given via the local name of the custom element. ' +
+    'Custom element is defined in loaded HTML document');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-interface-type-is-a-local-name.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-interface-type-is-a-local-name.html
new file mode 100644
index 0000000..306cfd3
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-interface-type-is-a-local-name.html
@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Document.createElement() and Document.createElementNS() create custom element of type, specified by localName argument</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If an element definition with matching localName, namespace, and TYPE is not registered with token's document, set TYPE to localName">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#extensions-to-document-interface-to-instantiate">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var name1 = 'x-a';
+    var name2 = 'x-b';
+    var GeneratedConstructor = doc.registerElement(name1);
+    var customElement = doc.createElement(name1, name2);
+
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be the local name of the custom element');
+}, 'Test Document.createElement() creates custom element of type, ' +
+    'specified by localName argument, if an element definition with matching localName, ' +
+    'namespace, and type is not registered');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var name1 = 'x-c';
+    var name2 = 'x-d';
+    var GeneratedConstructor = doc.registerElement(name1);
+    var customElement = doc.createElementNS(HTML_NAMESPACE, name1, name2);
+
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be the local name of the custom element');
+}, 'Test Document.createElementNS() creates custom element of type, ' +
+    'specified by localName argument, if an element definition with matching ' +
+    'localName, namespace, and type is not registered');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-interface-type-is-a-type-extension.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-interface-type-is-a-type-extension.html
new file mode 100644
index 0000000..1aefe32
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-interface-type-is-a-type-extension.html
@@ -0,0 +1,70 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Document.createElement() and Document.createElementNS() create custom element of type, specified by typeExtension argument</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If an element definition with matching localName, namespace, and TYPE is registered then typeExtension is a TYPE">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#extensions-to-document-interface-to-instantiate">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var name1 = 'x-a';
+    var GeneratedConstructor1 = doc.registerElement(name1);
+    var name2 = 'x-b';
+    var GeneratedConstructor2 = doc.registerElement(name2);
+    var customElement = doc.createElement(name1, name2);
+
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor2.prototype,
+        'Custom element type should be the type extension of the custom element');
+}, 'Test Document.createElement() creates custom element of type, ' +
+    'specified by typeExtension argument');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var name1 = 'x-c';
+    var GeneratedConstructor1 = doc.registerElement(name1);
+    var name2 = 'x-d';
+    var GeneratedConstructor2 = doc.registerElement(name2);
+    var customElement = doc.createElementNS(HTML_NAMESPACE, name1, name2);
+
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor2.prototype,
+        'Custom element type should be the type extension of the custom element');
+}, 'Test Document.createElementNS() creates custom element of type, ' +
+    'specified by typeExtension argument');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var name1 = 'x-e';
+    var name2 = 'x-f';
+    var GeneratedConstructor2 = doc.registerElement(name2);
+    var customElement = doc.createElement(name1, name2);
+
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor2.prototype,
+        'Custom element type should be the type extension of the custom element');
+}, 'Test Document.createElement() creates custom element of type, ' +
+    'specified by typeExtension argument. Definition for localName is absent');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var name1 = 'x-g';
+    var name2 = 'x-h';
+    var GeneratedConstructor2 = doc.registerElement(name2);
+    var customElement = doc.createElementNS(HTML_NAMESPACE, name1, name2);
+
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor2.prototype,
+        'Custom element type should be the type extension of the custom element');
+}, 'Test Document.createElementNS() creates custom element of type, ' +
+    'specified by typeExtension argument. Definition for localName is absent');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-is-attribute.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-is-attribute.html
new file mode 100644
index 0000000..bcb1bd0
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-is-attribute.html
@@ -0,0 +1,72 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Document.createElement() and Document.createElementNS() set IS attribute to type</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If TYPE is not the same as localName, set the value of ELEMENT's IS attribute to TYPE">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#extensions-to-document-interface-to-instantiate">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-a-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        doc.registerElement(name, {prototype: proto, extends: tagName});
+        var customElement = doc.createElement(tagName, name);
+        assert_equals(customElement.getAttribute('is'), name,
+            'Value of the IS attribute should be set to type by Document.createElement()');
+    });
+}, 'Test Document.createElement() sets the element\'s IS attribute value to type, ' +
+    'if type is not the same as localName');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var name = 'x-b-' + tagName;
+        var customElement = doc.createElement(tagName, name);
+        assert_equals(customElement.getAttribute('is'), name,
+            'Value of the IS attribute should be set to type by Document.createElement()');
+    });
+}, 'Test Document.createElement() sets the element\'s IS attribute value to type, ' +
+    'if type is not the same as localName and an element definition with matching ' +
+    'localName, namespace, and type is not registered');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-c-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        doc.registerElement(name, {prototype: proto, extends: tagName});
+        var customElement = doc.createElementNS(HTML_NAMESPACE, tagName, name);
+        assert_equals(customElement.getAttribute('is'), name,
+            'Value of the IS attribute should be set to type by Document.createElementNS()');
+    });
+}, 'Test Document.createElementNS() sets the element\'s IS attribute value to type, ' +
+    'if type is not the same as localName');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var name = 'x-d-' + tagName;
+        var customElement = doc.createElementNS(HTML_NAMESPACE, tagName, name);
+        assert_equals(customElement.getAttribute('is'), name,
+            'Value of the IS attribute should be set to type by Document.createElementNS()');
+    });
+}, 'Test Document.createElementNS() sets the element\'s IS attribute value to type, ' +
+    'if type is not the same as localNameand and an element definition with matching ' +
+    'localName, namespace, and type is not registered ');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-namespace.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-namespace.html
new file mode 100644
index 0000000..2f58b0d
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-namespace.html
@@ -0,0 +1,69 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Document.createElement() sets custom element namespace to HTML Namespace</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Namespace for createElement is HTML Namespace">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#extensions-to-document-interface-to-instantiate">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var name = 'x-a';
+    doc.registerElement(name);
+    var customElement = doc.createElement(name);
+    assert_equals(customElement.namespaceURI, HTML_NAMESPACE,
+        'Custom element namespace should be HTML Namespace');
+}, 'Test Document.createElement() sets custom element namespace to HTML Namespace');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var name = 'x-b';
+    var customElement = doc.createElement(name);
+    assert_equals(customElement.namespaceURI, HTML_NAMESPACE,
+        'Custom element namespace should be HTML Namespace');
+}, 'Test Document.createElement() sets custom element namespace to HTML Namespace ' +
+    'and an element definition with matching localName, namespace, and type is not registered');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-c-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        doc.registerElement(name, {
+            prototype: Object.create(proto),
+            extends: tagName
+        });
+        var customElement = doc.createElement(tagName, name);
+        assert_equals(customElement.namespaceURI, HTML_NAMESPACE,
+            'Custom element namespace for the element extending ' + tagName +
+            ' should be HTML Namespace');
+    });
+}, 'Document.createElement() sets custom element namespace to HTML Namespace. ' +
+    'Custom element is extending standard HTML tag');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var name = 'x-d-' + tagName;
+        var customElement = doc.createElement(tagName, name);
+        assert_equals(customElement.namespaceURI, HTML_NAMESPACE,
+            'Custom element namespace for the element with tag name ' + tagName +
+            ' and type name ' + name + ' should be HTML Namespace');
+    });
+}, 'Document.createElement() sets custom element namespace to HTML Namespace. ' +
+    'Document.createElement() is called with standard HTML tag name and ' +
+    'type without registered custom element of such type');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-type-extension-is-a-type.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-type-extension-is-a-type.html
new file mode 100644
index 0000000..080639f
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-type-extension-is-a-type.html
@@ -0,0 +1,48 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Document.createElement() and Document.createElementNS() create custom element of type, specified by typeExtension argument</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Let TYPE be typeExtension, or localName if typeExtension is not present">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#extensions-to-document-interface-to-instantiate">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-a-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {prototype: proto, extends: tagName});
+        var customElement = doc.createElement(tagName, name);
+
+        assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+            'Custom element type should be ' + name);
+    });
+}, 'Test Document.createElement() creates custom element of type, ' +
+    'specified by typeExtension argument');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-b-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {prototype: proto, extends: tagName});
+        var customElement = doc.createElementNS(HTML_NAMESPACE, tagName, name);
+
+        assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+            'Custom element type should be ' + name);
+    });
+}, 'Test Document.createElementNS() creates custom element of type, ' +
+    'specified by typeExtension argument');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-type-extension-unresolved.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-type-extension-unresolved.html
new file mode 100644
index 0000000..9df65fd
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-type-extension-unresolved.html
@@ -0,0 +1,50 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Document.createElement() and Document.createElementNS() create custom element of type, specified by localName argument</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If an element definition with matching localName, namespace, and TYPE is not registered with token's document, set TYPE to localName">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#extensions-to-document-interface-to-instantiate">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test (function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-a-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var customElement = doc.createElement(tagName, name);
+        assert_equals(Object.getPrototypeOf(customElement), Object.getPrototypeOf(obj),
+            'Unregistered custom element type should be a local name');
+
+        var GeneratedConstructor = doc.registerElement(name, {prototype: proto, extends: tagName});
+        assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+            'Registered custom element type should be the type extension');
+    });
+}, 'If typeExtension is unresolved when createElement called then local name is a type');
+
+
+test (function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-b-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var customElement = doc.createElementNS(HTML_NAMESPACE, tagName, name);
+        assert_equals(Object.getPrototypeOf(customElement), Object.getPrototypeOf(obj),
+            'Custom element type should be a local name');
+
+        var GeneratedConstructor = doc.registerElement(name, {prototype: proto, extends: tagName});
+        assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+            'Custom element type should be the type extension');
+    });
+}, 'If typeExtension is unresolved when createElementNS called then local name is a type');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-type-is-a-local-name.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-type-is-a-local-name.html
new file mode 100644
index 0000000..1d50977
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/create-element-type-is-a-local-name.html
@@ -0,0 +1,39 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Document.createElement() and Document.createElementNS() create custom element of type, specified by single localName argument</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Let TYPE be typeExtension, or localName if typeExtension is not present">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#extensions-to-document-interface-to-instantiate">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var name = 'x-a';
+    var GeneratedConstructor = doc.registerElement(name);
+    var customElement = doc.createElement(name);
+
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be the local name of the custom element');
+}, 'Test Document.createElement() creates custom element of type, ' +
+    'specified by single localName argument');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var name = 'x-b';
+    var GeneratedConstructor = doc.registerElement(name);
+    var customElement = doc.createElementNS(HTML_NAMESPACE, name);
+    assert_equals(Object.getPrototypeOf(customElement), GeneratedConstructor.prototype,
+        'Custom element type should be the local name of the custom element');
+}, 'Test Document.createElementNS() creates custom element of type, ' +
+    'specified by localName argument. Argument typeExtension is not passed');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/created-callback-create-element-ns.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/created-callback-create-element-ns.html
new file mode 100644
index 0000000..7f0bf98
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/created-callback-create-element-ns.html
@@ -0,0 +1,73 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Document.createElementNS() must enqueue created callback for registered custom element type</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Document.createElementNS() must enqueue created callback for registered custom element type">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#extensions-to-document-interface-to-instantiate">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var name = 'x-a';
+
+    doc.registerElement(name, {prototype: proto});
+    var customElement = doc.createElementNS(HTML_NAMESPACE, name);
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be enqueued by Document.createElementNS()');
+}, 'Test Document.createElementNS() without typeExtension argument enqueues created callback');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var name = 'x-b';
+
+    doc.registerElement(name, {prototype: proto});
+    var customElement = doc.createElementNS(HTML_NAMESPACE, name, name);
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be enqueued by Document.createElementNS()');
+}, 'Test Document.createElementNS() with typeExtension argument enqueues created callback');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var name = 'x-c';
+    var customElement = doc.createElementNS(HTML_NAMESPACE, name);
+    assert_equals(proto.createdCallbackCalledCounter, 0,
+        'Document.createElementNS() should not enqueue created callback ' +
+        'for unresolved custom element');
+
+    doc.registerElement(name, {prototype: proto});
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be called after custom element is registered');
+}, 'Document.createElementNS() should not enqueue created callback ' +
+    'for unresolved custom element');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-d-' + tagName;
+        var proto = newCustomElementPrototype(Object.create(obj.constructor.prototype));
+        doc.registerElement(name, {prototype: proto, extends: tagName});
+        var customElement = doc.createElementNS(HTML_NAMESPACE, tagName, name);
+
+        assert_equals(proto.createdCallbackCalledCounter, 1,
+            'Callback created should be enqueued by Document.createElementNS()');
+    });
+}, 'Test Document.createElementNS() enqueues created callback for custom elements ' +
+    'that are extensions of HTML5 elements');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/created-callback-create-element.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/created-callback-create-element.html
new file mode 100644
index 0000000..0a557e5
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/extensions-to-document-interface/created-callback-create-element.html
@@ -0,0 +1,73 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Document.createElement() must enqueue created callback for registered custom element type</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Document.createElement() must enqueue created callback for registered custom element type">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#extensions-to-document-interface-to-instantiate">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#types-of-callbacks">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var name = 'x-a';
+
+    doc.registerElement(name, {prototype: proto});
+    var customElement = doc.createElement(name);
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be enqueued by Document.createElement()');
+}, 'Test Document.createElement() without typeExtension argument enqueues created callback');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var name = 'x-b';
+
+    doc.registerElement(name, {prototype: proto});
+    var customElement = doc.createElement(name, name);
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be enqueued by Document.createElement()');
+}, 'Test Document.createElement() with typeExtension argument enqueues created callback');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = newHTMLElementPrototype();
+    var name = 'x-c';
+    var customElement = doc.createElement(name);
+    assert_equals(proto.createdCallbackCalledCounter, 0,
+        'Document.createElement() should not enqueue created callback ' +
+        'for unresolved custom element');
+
+    doc.registerElement(name, {prototype: proto});
+    assert_equals(proto.createdCallbackCalledCounter, 1,
+        'Callback created should be called after custom element is registered');
+}, 'Document.createElement() should not enqueue created callback ' +
+    'for unresolved custom element');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-d-' + tagName;
+        var proto = newCustomElementPrototype(Object.create(obj.constructor.prototype));
+        doc.registerElement(name, {prototype: proto, extends: tagName});
+        var customElement = doc.createElement(tagName, name);
+
+        assert_equals(proto.createdCallbackCalledCounter, 1,
+            'Callback created should be enqueued by Document.createElement()');
+    });
+}, 'Test Document.createElement() enqueues created callback for custom elements ' +
+    'that are extensions of HTML5 elements');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/non-configurable-constructor-property.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/non-configurable-constructor-property.html
new file mode 100644
index 0000000..c4ba076
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/non-configurable-constructor-property.html
@@ -0,0 +1,42 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>If prototype has a non-configurable property named constructor, Document.registerElement() throws NotSupportedError</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If  PROTOTYPE has a non-configurable property named constructor, throw a NotSupportedError and stop">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = Object.create(HTMLElement.prototype);
+    Object.defineProperty(proto, 'constructor', {configurable: false});
+    assert_throws('NotSupportedError', function() {
+        doc.registerElement('x-a', {prototype: proto});
+    }, 'Exception should be thrown in case of attempt to register element ' +
+        'with a non-configurable property named constructor');
+}, 'Test Document.registerElement() throws NotSupportedError ' +
+    'if prototype has a non-configurable property named constructor');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = Object.create(HTMLElement.prototype);
+    Object.defineProperty(proto, 'constructor', {configurable: true});
+    try {
+        doc.registerElement('x-b', {prototype: proto});
+    } catch (e) {
+        assert_unreached('Exception should not be thrown in case of attempt to register ' +
+            'element with a configurable property named constructor');
+    }
+}, 'Test Document.registerElement() accepts prototype with a configurable ' +
+    'property named constructor without throwing errors');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/prototype-is-interface-prototype-object.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/prototype-is-interface-prototype-object.html
new file mode 100644
index 0000000..25121c3
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/prototype-is-interface-prototype-object.html
@@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>If prototype is already an interface prototype object, Document.registerElement() throws a NotSupportedError</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If PROTOTYPE is already an interface prototype object for any interface object, throw a NotSupportedError and stop">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-a-' + tagName;
+        assert_throws('NotSupportedError', function() {
+            doc.registerElement(name, {prototype: obj.constructor.prototype});
+        }, 'Exception should be thrown in case of attempt to register element ' +
+            'if prototype is already an interface prototype object (' + name + ')');
+    });
+}, 'Test Document.registerElement() throws NotSupportedError ' +
+    'if prototype is already an interface prototype object');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = Object.create(HTMLElement.prototype);
+    doc.registerElement('x-b', {
+        prototype: proto
+    });
+    assert_throws('NotSupportedError', function() {
+        doc.registerElement('x-b', {
+            prototype: proto
+        });
+    }, 'Exception should be thrown if registring custom element type with already used prototype');
+}, 'Test Document.registerElement() throws NotSupportedError ' +
+    'if prototype is already used for another custom element type');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/unchanged-attribute.html b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/unchanged-attribute.html
new file mode 100644
index 0000000..3baa174
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/instantiating-custom-elements/unchanged-attribute.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Custom element's type is immutable.</title>
+<meta name="author" title="Bon-Yong Lee" href="mailto:bylee78@gmail.com">
+<meta name="assert" content="After a custom element is instantiated, changing the value of the is attribute must not affect this element's custom element type.">
+<link rel="help" href="http://w3c.github.io/webcomponents/spec/custom/#instantiating-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script type="text/javascript">
+test(function() {
+  var CustomButton = document.registerElement('custom-button', {
+    prototype: Object.create(HTMLButtonElement.prototype),
+    extends: 'button'
+  });
+  var customButton = document.createElement('button', 'custom-button');
+
+  assert_true(customButton instanceof CustomButton,
+              'A custom element is of the custom element type after ' +
+              'instantiation');
+  customButton.setAttribute('is', 'dirty');
+  assert_equals('dirty', customButton.getAttribute('is'),
+                'An attribute must be changed by method "setAttribute"');
+
+  assert_true(customButton instanceof CustomButton,
+              'A custom element is of the original custom element type even ' +
+              'after changing the \'is\' attribute');
+}, 'After a custom element is instantiated, changing the value of the is attribute must not affect this element\'s custom element type.');
+</script>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-default-namespace.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-default-namespace.html
new file mode 100644
index 0000000..02f57d8
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-default-namespace.html
@@ -0,0 +1,44 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Default namespace is HTML namespace</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Default namespace is HTML namespace">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-a');
+    var customElement = new GeneratedConstructor();
+
+    assert_equals(customElement.namespaceURI, HTML_NAMESPACE,
+        'Custom element namespace should be HTML namespace');
+}, 'Default namespace is HTML namespace');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-b-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {
+            prototype: proto,
+            extends: tagName
+        });
+        var customElement = new GeneratedConstructor();
+
+        assert_equals(customElement.namespaceURI, HTML_NAMESPACE,
+            'Custom element namespace should be HTML namespace');
+    });
+}, 'Default namespace is HTML namespace. Test constructor of extended HTML element');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-duplicate-definition.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-duplicate-definition.html
new file mode 100644
index 0000000..3f71897
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-duplicate-definition.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Check duplicate definition</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If there already exists a definition with the same TYPE, set ERROR to DuplicateDefinition and stop">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var name = 'x-a';
+    doc.registerElement(name);
+    assert_throws('NotSupportedError', function() {
+        doc.registerElement(name);
+    }, 'Exception should be thrown if definition with the same type already exists');
+}, 'Check duplicate definition');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var name = 'x-b';
+    doc.registerElement(name);
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        assert_throws('NotSupportedError', function() {
+            doc.registerElement(name, {
+                extends: tagName
+            });
+        }, 'Exception should be thrown if definition with the same type already exists');
+    });
+}, 'Check duplicate definition. Specify constructor');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var name = 'x-c';
+    doc.registerElement(name, {
+        prototype: Object.create(HTMLAnchorElement.prototype),
+        extends: 'a'
+    });
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        assert_throws('NotSupportedError', function() {
+            doc.registerElement(name, {
+                extends: tagName
+            });
+        }, 'Exception should be thrown if definition with the same type already exists');
+    });
+}, 'Check duplicate definition. Test different prototypes and extends');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-invalid-type.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-invalid-type.html
new file mode 100644
index 0000000..1718db6
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-invalid-type.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>If TYPE is an invalid custom element type, throw SyntaxError</title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="If TYPE is an invalid custom element type, set ERROR to InvalidType and stop.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    assert_throws('SyntaxError', function() { doc.registerElement('1xa2'); },
+                  'Registering invalid custom element type should throw SyntaxError');
+}, 'Registering invalid custom element type should throw SyntaxError');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-local-name-lowercased.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-local-name-lowercased.html
new file mode 100644
index 0000000..125e159
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-local-name-lowercased.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Custom element local name should be converted to lower case if document is an HTML document</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If DOCUMENT is an HTML document, convert NAME to lowercase">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-a-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {
+            prototype: proto,
+            extends: tagName.toUpperCase()
+        });
+        var customElement = new GeneratedConstructor();
+
+        assert_equals(customElement.localName, tagName, 'Local name should be lowercased');
+    });
+}, 'Custom element local name should be lowercased if document is an HTML document');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-name-is-null.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-name-is-null.html
new file mode 100644
index 0000000..2aa80c6
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-name-is-null.html
@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>If NAME is null then localName must be set to TYPE</title>
+<meta name="author" title="Vasiliy Degtyarev" href="mailto:vasya@unipro.ru">
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If NAME is null then localName must be set to TYPE">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var name = 'x-a';
+    var proto = Object.create(HTMLElement.prototype);
+    var GeneratedConstructor = doc.registerElement(name, {prototype: proto});
+    var customElement = new GeneratedConstructor();
+
+    assert_equals(customElement.localName, name, 'LocalName should be a type in case of ' +
+        'attempt to register a custom element and local name is not provided');
+}, 'If NAME is not specified then localName must be set to TYPE');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var name = 'x-b';
+    var proto = Object.create(HTMLElement.prototype);
+    var GeneratedConstructor = doc.registerElement(name, {prototype: proto, extends: null});
+    var customElement = new GeneratedConstructor();
+
+    assert_equals(customElement.localName, name, 'LocalName should be a type in case of ' +
+        'attempt to register a custom element and name is null');
+}, 'If NAME is null then localName must be set to TYPE');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-no-interface-for-name.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-no-interface-for-name.html
new file mode 100644
index 0000000..71c906b
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-no-interface-for-name.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>If element interface for name doesn't exists then error must be thrown</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If NAME was provided and is not null and if element interface for the name and namespace does not exist or is an interface for a custom element, set ERROR to InvalidName and stop">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    doc.registerElement('x-a');
+    assert_throws('NotSupportedError', function() {
+        doc.registerElement('x-b', {extends: 'x-a'});
+    }, 'Exception should be thrown in case of attempt to register ' +
+        'a custom element which extends another custom element');
+}, 'Exception should be thrown in case of attempt to register ' +
+    'a custom element which extends another custom element');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-svg-namespace-name-is-null.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-svg-namespace-name-is-null.html
new file mode 100644
index 0000000..5acf176
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-svg-namespace-name-is-null.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>If namespace is SVG namespace and name is null then error must be thrown</title>
+<meta name="author" title="Vasiliy Degtyarev" href="mailto:vasya@unipro.ru">
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If namespace is SVG namespace and name is null then error must be thrown">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = Object.create(SVGElement.prototype);
+    assert_throws('NotSupportedError', function() {
+        doc.registerElement('x-svg-a', {prototype: proto});
+    }, 'Exception should be thrown in case of attempt to register ' +
+        'a custom element with SVG namespace and name is not specified');
+}, 'Error should be thrown if namespace is SVG and local name is not specified');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = Object.create(SVGElement.prototype);
+    assert_throws('NotSupportedError', function() {
+        doc.registerElement('x-svg-b', {prototype: proto, extends: null});
+    }, 'Exception should be thrown in case of attempt to register ' +
+        'a custom element with SVG namespace and name is null');
+}, 'Error should be thrown if namespace is SVG and local name is null');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-svg-namespace.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-svg-namespace.html
new file mode 100644
index 0000000..940db30
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-svg-namespace.html
@@ -0,0 +1,27 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>For SVG prototype namespace is SVG namespace</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If PROTOTYPE's interface inherits from SVGElement, set NAMESPACE to SVG Namespace">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var proto = Object.create(SVGElement.prototype);
+    var GeneratedConstructor = doc.registerElement('x-a', {prototype: proto, extends: 'a'});
+    var customElement = new GeneratedConstructor();
+
+    assert_equals(customElement.namespaceURI, SVG_NAMESPACE,
+        'Custom element namespace should be SVG namespace');
+}, 'For SVG prototype namespace is SVG namespace');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-type-name-lowercased.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-type-name-lowercased.html
new file mode 100644
index 0000000..9e1bf3e
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/definition-construction-algorithm-type-name-lowercased.html
@@ -0,0 +1,42 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Custom element type should be converted to lower case</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Custom element type should be lowercased">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('X-A');
+    var customElement = new GeneratedConstructor();
+
+    assert_equals(customElement.localName, 'x-a', 'Custom element type should be lowercased');
+}, 'Custom element type should be lowercased. Test constructor');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var obj = doc.createElement(tagName);
+        var name = 'x-a-' + tagName;
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {
+            prototype: proto,
+            extends: tagName.toUpperCase()
+        });
+        var customElement = new GeneratedConstructor();
+
+        assert_equals(customElement.localName, tagName, 'Local name should be lowercased');
+    });
+}, 'Custom element type should be lowercased. Test constructor of extended HTML element');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/element-registration-algorithm-no-registry.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/element-registration-algorithm-no-registry.html
new file mode 100644
index 0000000..1dfd778
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/element-registration-algorithm-no-registry.html
@@ -0,0 +1,40 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>If document has no registry NotSupportedError is thrown</title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="If REGISTRY does not exist, set ERROR to NoRegistry and stop.">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#dfn-element-registration-algorithm">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = document.implementation.createDocument(null, 'test', null);
+    assert_throws('NotSupportedError', function(){
+                      doc.registerElement('x-a');
+                  }, 'Registering valid custom element in document ' +
+                      'without registry should throw NotSupportedError');
+
+}, 'Registering valid custom element without options in document ' +
+    'without registry should throw NotSupportedError');
+
+
+test(function() {
+    var doc = document.implementation.createDocument(null, 'test', null);
+    var proto = Object.create(HTMLElement.prototype);
+
+    assert_throws('NotSupportedError', function(){
+                      doc.registerElement('x-b', { prototype: proto, extends: 'a'});
+                  }, 'Registering valid custom element in document ' +
+                      'without registry should throw NotSupportedError');
+
+}, 'Registering valid custom element with options in document ' +
+    'without registry should throw NotSupportedError');
+</script>
+</body>
+</html>
\ No newline at end of file
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/extensions-to-document-interface/custom-element-name.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/extensions-to-document-interface/custom-element-name.html
new file mode 100644
index 0000000..fd02d63
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/extensions-to-document-interface/custom-element-name.html
@@ -0,0 +1,37 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Custom element local name is the lowercased value of the EXTENDS property, supplied to Document.registerElement()</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="Custom element local name is the lowercased value of the EXTENDS property">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#extensions-to-document-interface-to-register">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        var name = 'x-' + tagName;
+        var obj = doc.createElement(tagName);
+        var proto = Object.create(obj.constructor.prototype);
+        var GeneratedConstructor = doc.registerElement(name, {
+            prototype: proto,
+            extends: tagName
+        });
+        var customElement = new GeneratedConstructor();
+
+        assert_equals(customElement.localName, tagName.toLowerCase(),
+            'Custom element local name should be a lowercased value of the EXTENDS property, ' +
+            'supplied to Document.registerElement()');
+    });
+}, 'Custom element local name is the lowercased value of the EXTENDS property, ' +
+    'supplied to Document.registerElement()');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/extensions-to-document-interface/custom-element-prototype.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/extensions-to-document-interface/custom-element-prototype.html
new file mode 100644
index 0000000..476f5c8
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/extensions-to-document-interface/custom-element-prototype.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Test prototype object of a custom element</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="If PROTOTYPE is null, let PROTOTYPE be the result of invoking Object.create with HTMLElement's interface prototype object as only argument">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#extensions-to-document-interface-to-register">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var GeneratedConstructor = doc.registerElement('x-a');
+    var customElement = new GeneratedConstructor();
+
+    assert_class_string(customElement, 'HTMLElement',
+        'Custom element should be a HTMLElement, ' +
+        'if its type is registered without prototype');
+}, 'Custom element should have HTMLElement prototype, ' +
+    'if its type is registered without prototype');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-custom-tag-ref.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-custom-tag-ref.html
new file mode 100644
index 0000000..33c3646
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-custom-tag-ref.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html>
+<title>The :unresolved pseudoclass reference file</title>
+<link rel="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<style>
+    body {
+        background-color: white;
+    }
+</style>
+<body>
+    <p>Test passes if x-element background below is red</p>
+    <x-element style="background-color: red;">
+        x-element
+    </x-element>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-custom-tag.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-custom-tag.html
new file mode 100644
index 0000000..290e5b1
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-custom-tag.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html>
+<title>The :unresolved pseudoclass matching custom tag</title>
+<link rel="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="The :unresolved pseudoclass must match all custom elements whose created callback has not yet been invoked">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#unresolved-element-pseudoclass">
+<link rel="match" href="unresolved-element-pseudoclass-css-test-custom-tag-ref.html">
+<style>
+    :unresolved {
+        background-color: red;
+    }
+    body {
+        background-color: white;
+    }
+</style>
+<body>
+    <p>Test passes if x-element background below is red</p>
+    <x-element>
+        x-element
+    </x-element>
+</body>
+</html>
+
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-custom-tag-ref.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-custom-tag-ref.html
new file mode 100644
index 0000000..d49f3d7
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-custom-tag-ref.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html>
+<title>The :unresolved pseudoclass reference file</title>
+<link rel="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<style>
+    body {
+        background-color: white;
+    }
+</style>
+<body>
+    <p>Test passes if x-element background below is yellow</p>
+    <x-element style="background-color: yellow;">
+        x-element
+    </x-element>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-custom-tag.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-custom-tag.html
new file mode 100644
index 0000000..3cd7b41
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-custom-tag.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html>
+<title>The :unresolved pseudoclass matching custom tag</title>
+<link rel="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="The :unresolved pseudoclass must match all custom elements whose created callback has not yet been invoked">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#unresolved-element-pseudoclass">
+<link rel="match" href="unresolved-element-pseudoclass-css-test-registered-custom-tag-ref.html">
+<style>
+    :unresolved {
+        background-color: red;
+    }
+    x-element {
+        background-color: yellow;
+    }
+    body {
+        background-color: white;
+    }
+</style>
+<body onload="document.registerElement('x-element');">
+    <p>Test passes if x-element background below is yellow</p>
+    <x-element>
+        x-element
+    </x-element>
+</body>
+</html>
+
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-type-extension-ref.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-type-extension-ref.html
new file mode 100644
index 0000000..90baf95
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-type-extension-ref.html
@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html>
+<title>The :unresolved pseudoclass reference file</title>
+<link rel="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<style>
+    body {
+        background-color: white;
+    }
+</style>
+<body>
+    <p>Test passes if x-element background below is yellow</p>
+    <a is="x-element" style="background-color: yellow;">
+        x-element
+    </a>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-type-extension.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-type-extension.html
new file mode 100644
index 0000000..65921bd
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-registered-type-extension.html
@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<html>
+<title>The :unresolved pseudoclass matching type extension</title>
+<link rel="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="The :unresolved pseudoclass must match all custom elements whose created callback has not yet been invoked">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#unresolved-element-pseudoclass">
+<link rel="match" href="unresolved-element-pseudoclass-css-test-registered-type-extension-ref.html">
+<style>
+    :unresolved {
+        background-color: red;
+    }
+    a {
+        background-color: yellow;
+    }
+    body {
+        background-color: white;
+    }
+</style>
+<script>
+function registerXElement() {
+    var obj = document.createElement('a');
+    var proto = Object.create(obj.constructor.prototype);
+    document.registerElement('x-element', { prototype: proto, extends: 'a'});
+}
+</script>
+<body onload="registerXElement();">
+    <p>Test passes if x-element background below is yellow</p>
+    <a is="x-element">
+        x-element
+    </a>
+</body>
+</html>
+
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-type-extension-ref.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-type-extension-ref.html
new file mode 100644
index 0000000..9865f2e
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-type-extension-ref.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html>
+<title>The :unresolved pseudoclass reference file</title>
+<link rel="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<style>
+    body {
+        background-color: white;
+    }
+</style>
+<body>
+    <p>Test passes if x-element background below is red</p>
+    <a is="x-element" style="background-color: red;">
+        x-element
+    </a>
+</body>
+</html>
+
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-type-extension.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-type-extension.html
new file mode 100644
index 0000000..60f3912
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-css-test-type-extension.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html>
+<title>The :unresolved pseudoclass matching type extension</title>
+<link rel="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="The :unresolved pseudoclass must match all custom elements whose created callback has not yet been invoked">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#unresolved-element-pseudoclass">
+<link rel="match" href="unresolved-element-pseudoclass-css-test-type-extension-ref.html">
+<style>
+    :unresolved {
+        background-color: red;
+    }
+    body {
+        background-color: white;
+    }
+</style>
+<body>
+    <p>Test passes if x-element background below is red</p>
+    <a is="x-element">
+        x-element
+    </a>
+</body>
+</html>
+
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-matching-query-selector-all.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-matching-query-selector-all.html
new file mode 100644
index 0000000..aa8147a
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-matching-query-selector-all.html
@@ -0,0 +1,191 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>The :unresolved pseudoclass matching with Document.querySelectorAll()</title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="assert" content="The :unresolved pseudoclass must match all custom elements whose created callback has not yet been invoked">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#unresolved-element-pseudoclass">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-a></x-a>';
+    var queryResult = doc.querySelectorAll(':unresolved');
+
+    assert_equals(queryResult.length, 1,
+        'Unresolved custom element should be accessible by :unresolved pseudoclass');
+    assert_equals(queryResult.item(0).localName, 'x-a',
+        'Document.querySelectorAll(\':unresolved\') should return x-a element');
+}, 'Test that single unresolved custom element is accessible ' +
+    'by Document.querySelectorAll(\':unresolved\')');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-b></x-b>';
+    var queryResult = doc.querySelectorAll(':unresolved');
+
+    assert_equals(queryResult.length, 1,
+        'Unresolved custom element should be accessible by :unresolved pseudoclass');
+    assert_equals(queryResult.item(0).localName, 'x-b',
+        'Document.querySelectorAll(\':unresolved\') should return x-b element');
+
+    doc.registerElement('x-b');
+    queryResult = doc.querySelectorAll(':unresolved');
+
+    assert_equals(queryResult.length, 0,
+        'Registered custom element should not be accessible by :unresolved pseudoclass');
+}, 'Test that single registered custom element is not accessible by :unresolved');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-c></x-c><x-d></x-d>';
+    var queryResult = doc.querySelectorAll(':unresolved');
+
+    assert_equals(queryResult.length, 2,
+        'All unresolved custom element should be accessible by :unresolved pseudoclass');
+    assert_equals(queryResult.item(0).localName, 'x-c',
+        'First custom element returned by Document.querySelectorAll(\':unresolved\') ' +
+        'should be x-c');
+    assert_equals(queryResult.item(1).localName, 'x-d',
+        'Second custom element returned by Document.querySelectorAll(\':unresolved\') ' +
+        'should be x-d');
+
+    doc.registerElement('x-c');
+    queryResult = doc.querySelectorAll(':unresolved');
+
+    assert_equals(queryResult.length, 1,
+        'Only unresolved custom elements should be accessible by :unresolved pseudoclass');
+    assert_equals(queryResult.item(0).localName, 'x-d',
+        'Custom element returned by Document.querySelectorAll(\':unresolved\') ' +
+        'should be x-d');
+}, 'If there are more than one unresolved custom element then all of them accessible ' +
+    'by Document.querySelectorAll(\':unresolved\')');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var customElement = doc.createElement('x-e');
+    doc.body.appendChild(customElement);
+    var queryResult = doc.querySelectorAll(':unresolved');
+
+    assert_equals(queryResult.length, 1,
+        'Unresolved custom element should be accessible by :unresolved pseudoclass');
+    assert_equals(queryResult.item(0).localName, 'x-e',
+        'Custom element returned by Document.querySelectorAll(\':unresolved\') ' +
+        'should be x-e');
+}, 'Unresolved custom element, created via Document.createElement(), should be ' +
+    'accessible by Document.querySelectorAll(\':unresolved\')');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-f><x-g></x-g></x-f>';
+    var queryResult = doc.querySelectorAll(':unresolved');
+
+    assert_equals(queryResult.length, 2,
+        'All unresolved custom element should be accessible by :unresolved pseudoclass');
+    assert_equals(queryResult.item(0).localName, 'x-f',
+        'First custom element returned by Document.querySelectorAll(\':unresolved\') ' +
+        'should be x-f');
+    assert_equals(queryResult.item(1).localName, 'x-g',
+        'Second custom element returned by Document.querySelectorAll(\':unresolved\') ' +
+        'should be x-g');
+
+    doc.registerElement('x-g');
+    queryResult = doc.querySelectorAll(':unresolved');
+
+    assert_equals(queryResult.length, 1,
+        'Only unresolved custom elements should be accessible by :unresolved pseudoclass');
+    assert_equals(queryResult.item(0).localName, 'x-f',
+        'Custom element returned by Document.querySelectorAll(\':unresolved\') ' +
+        'should be x-f');
+}, 'All unresolved custom element including nested ones are accessible ' +
+    'by Document.querySelectorAll(\':unresolved\')');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var queryResult = doc.querySelectorAll(':unresolved');
+
+    assert_equals(queryResult.length, 1,
+        'Unresolved custom element should be accessible by ' +
+        'Document.querySelectorAll(\':unresolved\')');
+    assert_equals(queryResult.item(0).localName, 'x-element',
+        'Custom element returned by Document.querySelectorAll(\':unresolved\') ' +
+        'should be x-element');
+}, 'Unresolved custom element should be accessible by ' +
+    'Document.querySelectorAll(\':unresolved\') in a loaded document');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        if (HTML5_DOCUMENT_ELEMENTS.indexOf(tagName) === -1) {
+            var obj = doc.createElement(tagName);
+            var name = 'x-h-' + tagName;
+            var id = 'x-h-' + tagName + '-id';
+            if (HTML5_TABLE_ELEMENTS.indexOf(tagName) !== -1) {
+                doc.body.innerHTML =
+                    '<table>' +
+                    '<' + tagName + ' id="' + id + '" is="' + name + '"></' + tagName + '>' +
+                    '</table>';
+            } else {
+                doc.body.innerHTML =
+                    '<' + tagName + ' id="' + id + '" is="' + name + '"></' + tagName + '>';
+            }
+            var queryResult = doc.querySelectorAll(':unresolved');
+
+            assert_not_equals(queryResult, null,
+                'Unresolved custom element should be accessible by :unresolved pseudoclass');
+            assert_equals(queryResult.item(0).id, id,
+                'ID of element returned by Document.querySelectorAll(\':unresolved\') ' +
+                'should be ' + id);
+
+            var proto = Object.create(obj.constructor.prototype);
+            doc.registerElement(name, {prototype: proto, extends: tagName});
+            var queryResult2 = doc.querySelectorAll(':unresolved');
+
+            assert_equals(queryResult2.length, 0,
+                'Registered custom element should not be accessible by :unresolved pseudoclass');
+        }
+    });
+}, 'Test that Document.querySelectorAll(\':unresolved\') returns unresolved custom elements, ' +
+    'extending HTML elements by IS attribute');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-i><a is="x-j"></a></x-i><x-k></x-k><b is="x-l"/>';
+    var queryResult = doc.querySelectorAll(':unresolved');
+
+    assert_equals(queryResult.length, 4,
+        'All unresolved custom element should be accessible by :unresolved pseudoclass');
+
+    var elementNames = [
+        queryResult.item(0).localName,
+        queryResult.item(1).localName,
+        queryResult.item(2).localName,
+        queryResult.item(3).localName];
+    assert_array_equals(elementNames, ['x-i', 'a', 'x-k', 'b'],
+        'Document.querySelectorAll(\':unresolved\') return unexpected result');
+
+    var isAttributes = [
+        queryResult.item(0).getAttribute('is'),
+        queryResult.item(1).getAttribute('is'),
+        queryResult.item(2).getAttribute('is'),
+        queryResult.item(3).getAttribute('is')];
+    assert_array_equals(isAttributes, [null, 'x-j', null, 'x-l'],
+        'Document.querySelectorAll(\':unresolved\') return unexpected result');
+}, 'Test Document.querySelectorAll(\':unresolved\') returns mix of custom elements of different types');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-matching-query-selector.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-matching-query-selector.html
new file mode 100644
index 0000000..b4dff82
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-element-pseudoclass/unresolved-element-pseudoclass-matching-query-selector.html
@@ -0,0 +1,162 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>The :unresolved pseudoclass matching with Document.querySelector()</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="The :unresolved pseudoclass must match all custom elements whose created callback has not yet been invoked">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#unresolved-element-pseudoclass">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-a></x-a>';
+    var customElement = doc.querySelector(':unresolved');
+
+    assert_not_equals(customElement, null,
+        'Unresolved custom element should be accessible by :unresolved');
+    assert_equals(customElement.localName, 'x-a',
+        'Custom element returned by Document.querySelector(\':unresolved\') should be x-a');
+}, 'Test that unresolved custom element is accessible by Document.querySelector(\':unresolved\')');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-b></x-b>';
+    var customElement = doc.querySelector(':unresolved');
+    assert_not_equals(customElement, null,
+        'Unresolved custom element should be accessible by :unresolved');
+    assert_equals(customElement.localName, 'x-b',
+        'Custom element returned by Document.querySelector(\':unresolved\') should be x-b');
+
+    doc.registerElement('x-b');
+    customElement = doc.querySelector(':unresolved');
+    assert_equals(customElement, null,
+        'Registered custom element should not be accessible by :unresolved pseudoclass');
+}, 'Test that registered custom element are not accessible by :unresolved');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-c></x-c><x-d></x-d>';
+    var customElement = doc.querySelector(':unresolved');
+    assert_not_equals(customElement, null,
+        'Unresolved custom element should be accessible by :unresolved pseudoclass');
+    assert_equals(customElement.localName, 'x-c',
+        'Custom element returned by Document.querySelector(\':unresolved\') should be x-c');
+
+    doc.registerElement('x-c');
+    customElement = doc.querySelector(':unresolved');
+    assert_not_equals(customElement, null,
+        'Unresolved custom elements should be accessible by :unresolved pseudoclass');
+    assert_equals(customElement.localName, 'x-d',
+        'Custom element returned by Document.querySelector(\':unresolved\') should be x-d');
+}, 'If there are more than one unresolved custom element, all of them should be ' +
+    'accessible by :unresolved pseudoclass');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var customElement = doc.createElement('x-e');
+    doc.body.appendChild(customElement);
+    var queryResult = doc.querySelector(':unresolved');
+
+    assert_not_equals(queryResult, null,
+        'Unresolved custom element should be accessible by :unresolved');
+    assert_equals(queryResult.localName, 'x-e',
+        'Custom element returned by Document.querySelector(\':unresolved\') should be x-e');
+}, 'Unresolved custom element, created via Document.createElement(), should be ' +
+    'accessible by Document.querySelector(\':unresolved\')');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<div><x-f></x-f><div>';
+    var customElement = doc.querySelector(':unresolved');
+
+    assert_not_equals(customElement, null,
+        'Unresolved custom element should be accessible by :unresolved');
+    assert_equals(customElement.localName, 'x-f',
+        'Custom element returned by Document.querySelector(\':unresolved\') should be x-f');
+}, 'Unresolved custom element inside div element should be accessible by ' +
+    ':unresolved pseudoclass');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-h><x-g></x-g></x-h>';
+    var customElement = doc.querySelector(':unresolved');
+
+    assert_not_equals(customElement, null,
+        'Unresolved custom element should be accessible by :unresolved pseudoclass');
+    assert_equals(customElement.localName, 'x-h',
+        'Custom element returned by Document.querySelector(\':unresolved\') ' +
+        'should be x-h');
+
+    doc.registerElement('x-h');
+    customElement = doc.querySelector(':unresolved');
+
+    assert_not_equals(customElement, null,
+        'Unresolved custom element should be accessible by :unresolved pseudoclass');
+	assert_equals(customElement.localName, 'x-g',
+        'Custom element returned by Document.querySelector(\':unresolved\') ' +
+        'should be x-g');
+}, 'All unresolved custom element including nested ones should be accessible ' +
+    'by Document.querySelector(\':unresolved\')');
+
+
+testInIFrame('../../resources/x-element.html', function(doc) {
+    var customElement = doc.querySelector(':unresolved');
+
+    assert_not_equals(customElement, null,
+        'Unresolved custom element should be accessible by :unresolved');
+    assert_equals(customElement.localName, 'x-element',
+        'Custom element returned by Document.querySelector(\':unresolved\') should be x-element');
+}, 'Document.querySelector(): Unresolved custom element should be accessible by :unresolved ' +
+    'in loaded document');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+
+    HTML5_ELEMENTS.forEach(function(tagName) {
+        if (HTML5_DOCUMENT_ELEMENTS.indexOf(tagName) === -1) {
+            var obj = doc.createElement(tagName);
+            var name = 'x-i-' + tagName;
+            var id = 'x-i-' + tagName + '-id';
+            if (HTML5_TABLE_ELEMENTS.indexOf(tagName) !== -1) {
+                doc.body.innerHTML =
+                    '<table>' +
+                    '<' + tagName + ' id="' + id + '" is="' + name + '"></' + tagName + '>' +
+                    '</table>';
+            } else {
+                doc.body.innerHTML =
+                    '<' + tagName + ' id="' + id + '" is="' + name + '"></' + tagName + '>';
+            }
+            var customElement = doc.querySelector(':unresolved');
+
+            assert_not_equals(customElement, null,
+                'Unresolved custom element should be accessible by :unresolved pseudoclass');
+            assert_equals(customElement.id, id,
+                'ID of element returned by Document.querySelector(\':unresolved\') ' +
+                'should be ' + id);
+
+            var proto = Object.create(obj.constructor.prototype);
+            doc.registerElement(name, {prototype: proto, extends: tagName});
+            var customElement2 = doc.querySelector(':unresolved');
+
+            assert_equals(customElement2, null,
+                'Registered custom element should not be accessible by :unresolved pseudoclass');
+        }
+    });
+}, 'Test that Document.querySelector(\':unresolved\') returns custom element, ' +
+    'extending HTML elements by IS attribute');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-elements-interface-html-element.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-elements-interface-html-element.html
new file mode 100644
index 0000000..e8d66d1
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-elements-interface-html-element.html
@@ -0,0 +1,57 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Unresolved element interface must be HTMLElement, if the namespace is HTML Namespace</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="When an unresolved element is created, it's element interface must be HTMLElement, if the namespace is HTML Namespace">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML = '<x-a id="x-a"></x-a>';
+    var customElement = doc.querySelector('#x-a');
+
+    assert_not_equals(customElement, null, 'Unregistered custom element should not be null');
+
+    assert_class_string(customElement, 'HTMLElement',
+        'Unresolved custom element must be a HTML element');
+}, 'Test interface of unresolved element, created via innerHTML property');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var customElement = doc.createElement('x-b');
+
+    assert_class_string(customElement, 'HTMLElement',
+        'Unresolved custom element must be a HTML element');
+}, 'Test interface of unresolved element, created by Document.createElement');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var customElement = doc.createElementNS(HTML_NAMESPACE, 'x-c');
+
+    assert_class_string(customElement, 'HTMLElement',
+        'Unresolved custom element must be a HTML element');
+}, 'Test interface of unresolved element, created by Document.createElementNS');
+
+
+testInIFrame('../resources/x-element.html', function(doc) {
+    var customElement = doc.getElementById('x-element');
+
+    assert_not_equals(customElement, null, 'Unregistered custom element should not be null');
+
+    assert_class_string(customElement, 'HTMLElement',
+        'Unresolved custom element must be a HTML element');
+}, 'Test unresolved element interface in loaded HTML document');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-elements-interface-html-unknown-element.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-elements-interface-html-unknown-element.html
new file mode 100644
index 0000000..cc3c2c2
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-elements-interface-html-unknown-element.html
@@ -0,0 +1,54 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Unresolved element interface must be HTMLUnknownElement, if the namespace is neither HTML Namespace nor SVG Namespace</title>
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="When an unresolved element is created, it's element interface must be HTMLUnknownElement, if the namespace is neither HTML Namespace nor SVG Namespace">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+var MATHML_NAMESPACE = 'http://www.w3.org/1998/Math/MathML';
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML =
+        '<math xmlns="' + MATHML_NAMESPACE + '">' +
+            '<x-a id="x-a"></x-a>' +
+        '</math>';
+    var xa = doc.querySelector('#x-a');
+
+    assert_not_equals(xa, null, 'Unregistered custom element should not be null');
+
+    // According https://code.google.com/p/chromium/issues/detail?id=336377
+    // expected class string is Element
+    assert_class_string(xa, 'Element', 'Unresolved custom element must be an Element');
+}, 'Test interface of unresolved element with MathML namespace, created via innerHTML property');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    var xa = doc.createElementNS(MATHML_NAMESPACE, 'x-b');
+
+    assert_class_string(xa, 'Element',
+        'Unresolved custom element must be a HTMLUnknownElement');
+}, 'Test interface of unresolved element with MathML namespace, ' +
+    'created by Document.createElementNS');
+
+
+testInIFrame('../resources/x-mathml-element.html', function(doc) {
+    var customElement = doc.getElementById('x-math-element');
+
+    assert_not_equals(customElement, null, 'Unregistered custom element should not be null');
+
+    assert_class_string(customElement, 'Element',
+        'Unresolved custom element must be a Element');
+}, 'Test interface of unresolved element in loaded HTML document with embedded MathML elements');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-elements-interface-svg-element.html b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-elements-interface-svg-element.html
new file mode 100644
index 0000000..2020350
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/registering-custom-elements/unresolved-elements-interface-svg-element.html
@@ -0,0 +1,48 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>Unresolved element interface must be SVGElement, if the namespace is SVG Namespace</title>
+<meta name="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+<meta name="author" title="Vasiliy Degtyarev" href="mailto:vasya@unipro.ru">
+<meta name="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+<meta name="assert" content="When an unresolved element is created, it's element interface must be SVGElement if the namespace is SVG Namespace">
+<link rel="help" href="http://www.w3.org/TR/custom-elements/#registering-custom-elements">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+</head>
+<body>
+<div id="log"></div>
+<script>
+test(function() {
+    var doc = newHTMLDocument();
+    var xsvg = doc.createElementNS(SVG_NAMESPACE, 'x-svg');
+
+    assert_class_string(xsvg, 'SVGElement', 'Unresolved custom element must be a SVG element');
+}, 'Test interface of unresolved element with valid name, created by Document.createElementNS()');
+
+
+test(function() {
+    var doc = newHTMLDocument();
+    doc.body.innerHTML =
+        '<svg xmlns=' + SVG_NAMESPACE + ' version="1.1">' +
+            '<x-svg-a id="x-svg"></x-svg-a>' +
+        '</svg>';
+    var xsvg = doc.querySelector('#x-svg');
+
+    assert_class_string(xsvg, 'SVGElement', 'Unresolved custom element must be a SVG element');
+}, 'Test interface of unresolved element with valid name, created via innerHTML property');
+
+
+testInIFrame('../resources/x-svg-element.html', function(doc) {
+    var xsvg = doc.getElementById('x-svg-element');
+
+    assert_not_equals(xsvg, null, 'Unresolved custom element should not be null');
+
+    assert_class_string(xsvg, 'SVGElement',
+        'Unresolved custom element must be a SVG element');
+}, 'Test interface of unresolved element in loaded HTML document with embedded SVG elements');
+</script>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/resources/blank.html b/src/third_party/web_platform_tests/custom-elements/resources/blank.html
new file mode 100644
index 0000000..2e5697b
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/resources/blank.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Blank document</title>
+    <link rel="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+</head>
+<body>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/resources/import-master-async.html b/src/third_party/web_platform_tests/custom-elements/resources/import-master-async.html
new file mode 100644
index 0000000..0ecaafb
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/resources/import-master-async.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <title>Import Master Document (asynchronous)</title>
+        <link rel="import" href="import.html" async>
+    </head>
+    <body>
+        <p>Master document body</p>
+    </body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/resources/import-master.html b/src/third_party/web_platform_tests/custom-elements/resources/import-master.html
new file mode 100644
index 0000000..d91bcb9
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/resources/import-master.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <title>Import Master Document</title>
+        <link rel="import" href="import.html">
+    </head>
+    <body>
+        <p>Master document body</p>
+    </body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/resources/import.html b/src/third_party/web_platform_tests/custom-elements/resources/import.html
new file mode 100644
index 0000000..dddc467
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/resources/import.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <title>Import Document</title>
+    </head>
+    <body>
+        <p>Import Document body</p>
+    </body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/resources/register-and-create-custom-element.html b/src/third_party/web_platform_tests/custom-elements/resources/register-and-create-custom-element.html
new file mode 100644
index 0000000..3aabff2
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/resources/register-and-create-custom-element.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Register and create custom element</title>
+    <link rel="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+    <link rel="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+</head>
+<body>
+    <div id="log"></div>
+    <script>
+        var proto = Object.create(HTMLElement.prototype);
+        proto.createdCallback = function() {
+            document.querySelector('#log').textContent = 'Created callback was called';
+        };
+        document.registerElement('x-element', {prototype: proto});
+    </script>
+    <x-element id="x-element"></x-element>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/resources/x-element.html b/src/third_party/web_platform_tests/custom-elements/resources/x-element.html
new file mode 100644
index 0000000..0c0d2da
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/resources/x-element.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>x-element custom element</title>
+    <link rel="author" title="Sergey G. Grekhov" href="mailto:sgrekhov@unipro.ru">
+</head>
+<body>
+    <x-element id="x-element"></x-element>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/resources/x-mathml-element.html b/src/third_party/web_platform_tests/custom-elements/resources/x-mathml-element.html
new file mode 100644
index 0000000..3efdc2d
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/resources/x-mathml-element.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Custom element in MathML namespace</title>
+    <link rel="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+</head>
+<body>
+    <math xmlns="http://www.w3.org/1998/Math/MathML">
+        <x-math-element id="x-math-element"></x-math-element>
+    </math>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/resources/x-svg-element.html b/src/third_party/web_platform_tests/custom-elements/resources/x-svg-element.html
new file mode 100644
index 0000000..6cea857
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/resources/x-svg-element.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>SVG custom element</title>
+    <link rel="author" title="Aleksei Yu. Semenov" href="mailto:a.semenov@unipro.ru">
+</head>
+<body>
+    <svg height="100" width="100">
+        <x-svg-element id="x-svg-element"></x-element>
+    </svg>
+</body>
+</html>
diff --git a/src/third_party/web_platform_tests/custom-elements/testcommon.js b/src/third_party/web_platform_tests/custom-elements/testcommon.js
new file mode 100644
index 0000000..5cddbe8
--- /dev/null
+++ b/src/third_party/web_platform_tests/custom-elements/testcommon.js
@@ -0,0 +1,286 @@
+/*
+Distributed under both the W3C Test Suite License [1] and the W3C
+3-clause BSD License [2]. To contribute to a W3C Test Suite, see the
+policies and contribution forms [3].
+
+[1] http://www.w3.org/Consortium/Legal/2008/04-testsuite-license
+[2] http://www.w3.org/Consortium/Legal/2008/03-bsd-license
+[3] http://www.w3.org/2004/10/27-testcases
+ */
+
+"use strict";
+
+var HTML5_ELEMENTS = [ 'a', 'abbr', 'address', 'area', 'article', 'aside',
+        'audio', 'b', 'base', 'bdi', 'bdo', 'blockquote', 'body', 'br',
+        'button', 'canvas', 'caption', 'cite', 'code', 'col', 'colgroup',
+        'command', 'datalist', 'dd', 'del', 'details', 'dfn', 'dialog', 'div',
+        'dl', 'dt', 'em', 'embed', 'fieldset', 'figcaption', 'figure',
+        'footer', 'form', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'head', 'header',
+        'hgroup', 'hr', 'html', 'i', 'iframe', 'img', 'input', 'ins', 'kbd',
+        'keygen', 'label', 'legend', 'li', 'link', 'map', 'mark', 'menu',
+        'meta', 'meter', 'nav', 'noscript', 'object', 'ol', 'optgroup',
+        'option', 'output', 'p', 'param', 'pre', 'progress', 'q', 'rp', 'rt',
+        'ruby', 's', 'samp', 'script', 'section', 'select', 'small', 'source',
+        'span', 'strong', 'style', 'sub', 'table', 'tbody', 'td', 'textarea',
+        'tfoot', 'th', 'thead', 'time', 'title', 'tr', 'track', 'u', 'ul',
+        'var', 'video', 'wbr' ];
+
+var HTML5_DOCUMENT_ELEMENTS = [ 'html', 'head', 'body' ];
+
+var HTML5_TABLE_ELEMENTS = [ 'caption', 'col', 'colgroup', 'tbody', 'td',
+        'tfoot', 'th', 'thead', 'tr' ];
+
+var EXTENDER_CHARS = [ 0x00B7, 0x02D0, 0x02D1, 0x0387, 0x0640, 0x0E46, 0x0EC6,
+        0x3005, 0x3031, 0x3032, 0x3033, 0x3034, 0x3035, 0x309D, 0x309E, 0x30FC,
+        0x30FD, 0x30FE ];
+
+var COMBINING_CHARS = [ 0x0300, 0x0301, 0x0302, 0x0303, 0x0304, 0x0305, 0x0306,
+        0x0307, 0x0308, 0x0309, 0x030A, 0x030B, 0x030C, 0x030D, 0x030E, 0x030F,
+        0x0310, 0x0311, 0x0312, 0x0313, 0x0314, 0x0315, 0x0316, 0x0317, 0x0318,
+        0x0319, 0x031A, 0x031B, 0x031C, 0x031D, 0x031E, 0x031F, 0x0320, 0x0321,
+        0x0322, 0x0323, 0x0324, 0x0325, 0x0326, 0x0327, 0x0328, 0x0329, 0x032A,
+        0x032B, 0x032C, 0x032D, 0x032E, 0x032F, 0x0330, 0x0331, 0x0332, 0x0333,
+        0x0334, 0x0335, 0x0336, 0x0337, 0x0338, 0x0339, 0x033A, 0x033B, 0x033C,
+        0x033D, 0x033E, 0x033F, 0x0340, 0x0341, 0x0342, 0x0343, 0x0344, 0x0345,
+        0x0360, 0x0361, 0x0483, 0x0484, 0x0485, 0x0486, 0x0591, 0x0592, 0x0593,
+        0x0594, 0x0595, 0x0596, 0x0597, 0x0598, 0x0599, 0x05A0, 0x05A1, 0x05A3,
+        0x05A4, 0x05A5, 0x05A6, 0x05A7, 0x05A8, 0x05A9, 0x05AA, 0x05AB, 0x05AC,
+        0x05AD, 0x05AE, 0x05AF, 0x05B0, 0x05B1, 0x05B2, 0x05B3, 0x05B4, 0x05B5,
+        0x05B6, 0x05B7, 0x05B8, 0x05B9, 0x05BB, 0x05BC, 0x05BD, 0x05BF, 0x05C1,
+        0x05C2, 0x05C4, 0x064B, 0x064C, 0x064D, 0x064E, 0x064F, 0x0650, 0x0651,
+        0x0652, 0x0670, 0x06D6, 0x06D7, 0x06D8, 0x06D9, 0x06DA, 0x06DB, 0x06DC,
+        0x06DD, 0x06DE, 0x06DF, 0x06E0, 0x06E1, 0x06E2, 0x06E3, 0x06E4, 0x06E7,
+        0x06E8, 0x06EA, 0x06EB, 0x06EC, 0x06ED, 0x0901, 0x0902, 0x0903, 0x093C,
+        0x093E, 0x093F, 0x0940, 0x0941, 0x0942, 0x0943, 0x0944, 0x0945, 0x0946,
+        0x0947, 0x0948, 0x0949, 0x094A, 0x094B, 0x094C, 0x094D, 0x0951, 0x0952,
+        0x0953, 0x0954, 0x0962, 0x0963, 0x0981, 0x0982, 0x0983, 0x09BC, 0x09BE,
+        0x09BF, 0x09C0, 0x09C1, 0x09C2, 0x09C3, 0x09C4, 0x09C7, 0x09C8, 0x09CB,
+        0x09CC, 0x09CD, 0x09D7, 0x09E2, 0x09E3, 0x0A02, 0x0A3C, 0x0A3E, 0x0A3F,
+        0x0A40, 0x0A41, 0x0A42, 0x0A47, 0x0A48, 0x0A4B, 0x0A4C, 0x0A4D, 0x0A70,
+        0x0A71, 0x0A81, 0x0A82, 0x0A83, 0x0ABC, 0x0ABE, 0x0ABF, 0x0AC0, 0x0AC1,
+        0x0AC2, 0x0AC3, 0x0AC4, 0x0AC5, 0x0AC7, 0x0AC8, 0x0AC9, 0x0ACB, 0x0ACC,
+        0x0ACD, 0x0B01, 0x0B02, 0x0B03, 0x0B3C, 0x0B3E, 0x0B3F, 0x0B40, 0x0B41,
+        0x0B42, 0x0B43, 0x0B47, 0x0B48, 0x0B4B, 0x0B4C, 0x0B4D, 0x0B56, 0x0B57,
+        0x0B82, 0x0B83, 0x0BBE, 0x0BBF, 0x0BC0, 0x0BC1, 0x0BC2, 0x0BC6, 0x0BC7,
+        0x0BC8, 0x0BCA, 0x0BCB, 0x0BCC, 0x0BCD, 0x0BD7, 0x0C01, 0x0C02, 0x0C03,
+        0x0C3E, 0x0C3F, 0x0C40, 0x0C41, 0x0C42, 0x0C43, 0x0C44, 0x0C46, 0x0C47,
+        0x0C48, 0x0C4A, 0x0C4B, 0x0C4C, 0x0C4D, 0x0C55, 0x0C56, 0x0C82, 0x0C83,
+        0x0CBE, 0x0CBF, 0x0CC0, 0x0CC1, 0x0CC2, 0x0CC3, 0x0CC4, 0x0CC6, 0x0CC7,
+        0x0CC8, 0x0CCA, 0x0CCB, 0x0CCC, 0x0CCD, 0x0CD5, 0x0CD6, 0x0D02, 0x0D03,
+        0x0D3E, 0x0D3F, 0x0D40, 0x0D41, 0x0D42, 0x0D43, 0x0D46, 0x0D47, 0x0D48,
+        0x0D4A, 0x0D4B, 0x0D4C, 0x0D4D, 0x0D57, 0x0E31, 0x0E34, 0x0E35, 0x0E36,
+        0x0E37, 0x0E38, 0x0E39, 0x0E3A, 0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B,
+        0x0E4C, 0x0E4D, 0x0E4E, 0x0EB1, 0x0EB4, 0x0EB5, 0x0EB6, 0x0EB7, 0x0EB8,
+        0x0EB9, 0x0EBB, 0x0EBC, 0x0EC8, 0x0EC9, 0x0ECA, 0x0ECB, 0x0ECC, 0x0ECD,
+        0x0F18, 0x0F19, 0x0F35, 0x0F37, 0x0F39, 0x0F3E, 0x0F3F, 0x0F71, 0x0F72,
+        0x0F73, 0x0F74, 0x0F75, 0x0F76, 0x0F77, 0x0F78, 0x0F79, 0x0F7A, 0x0F7B,
+        0x0F7C, 0x0F7D, 0x0F7E, 0x0F7F, 0x0F80, 0x0F81, 0x0F82, 0x0F83, 0x0F84,
+        0x0F86, 0x0F87, 0x0F88, 0x0F89, 0x0F8A, 0x0F8B, 0x0F90, 0x0F91, 0x0F92,
+        0x0F93, 0x0F94, 0x0F95, 0x0F97, 0x0F99, 0x0F9A, 0x0F9B, 0x0F9C, 0x0F9D,
+        0x0F9E, 0x0F9F, 0x0FA0, 0x0FA1, 0x0FA2, 0x0FA3, 0x0FA4, 0x0FA5, 0x0FA6,
+        0x0FA7, 0x0FA8, 0x0FA9, 0x0FAA, 0x0FAB, 0x0FAC, 0x0FAD, 0x0FB1, 0x0FB2,
+        0x0FB3, 0x0FB4, 0x0FB5, 0x0FB6, 0x0FB7, 0x0FB9, 0x20D0, 0x20D1, 0x20D2,
+        0x20D3, 0x20D4, 0x20D5, 0x20D6, 0x20D7, 0x20D8, 0x20D9, 0x20DA, 0x20DB,
+        0x20DC, 0x20E1, 0x302A, 0x302B, 0x302C, 0x302D, 0x302E, 0x302F, 0x3099,
+        0x309A ];
+
+var BASE_CHARS_SINGLE = [ 0x0386, 0x038C, 0x03DA, 0x03DC, 0x03DE, 0x03E0,
+        0x0559, 0x06D5, 0x093D, 0x09B2, 0x0A5E, 0x0A8D, 0x0ABD, 0x0AE0, 0x0B3D,
+        0x0B9C, 0x0CDE, 0x0E30, 0x0E84, 0x0E8A, 0x0E8D, 0x0EA5, 0x0EA7, 0x0EB0,
+        0x0EBD, 0x1100, 0x1109, 0x113C, 0x113E, 0x1140, 0x114C, 0x114E, 0x1150,
+        0x1159, 0x1163, 0x1165, 0x1167, 0x1169, 0x1175, 0x119E, 0x11A8, 0x11AB,
+        0x11BA, 0x11EB, 0x11F0, 0x11F9, 0x1F59, 0x1F5B, 0x1F5D, 0x1FBE, 0x2126,
+        0x212E ];
+
+var BASE_CHARS_RANGES = [ 0x0041, 0x005A, 0x0061, 0x007A, 0x00C0, 0x00D6,
+        0x00D8, 0x00F6, 0x00F8, 0x00FF, 0x0100, 0x0131, 0x0134, 0x013E, 0x0141,
+        0x0148, 0x014A, 0x017E, 0x0180, 0x01C3, 0x01CD, 0x01F0, 0x01F4, 0x01F5,
+        0x01FA, 0x0217, 0x0250, 0x02A8, 0x02BB, 0x02C1, 0x0388, 0x038A, 0x038E,
+        0x03A1, 0x03A3, 0x03CE, 0x03D0, 0x03D6, 0x03E2, 0x03F3, 0x0401, 0x040C,
+        0x040E, 0x044F, 0x0451, 0x045C, 0x045E, 0x0481, 0x0490, 0x04C4, 0x04C7,
+        0x04C8, 0x04CB, 0x04CC, 0x04D0, 0x04EB, 0x04EE, 0x04F5, 0x04F8, 0x04F9,
+        0x0531, 0x0556, 0x0561, 0x0586, 0x05D0, 0x05EA, 0x05F0, 0x05F2, 0x0621,
+        0x063A, 0x0641, 0x064A, 0x0671, 0x06B7, 0x06BA, 0x06BE, 0x06C0, 0x06CE,
+        0x06D0, 0x06D3, 0x06E5, 0x06E6, 0x0905, 0x0939, 0x0958, 0x0961, 0x0985,
+        0x098C, 0x098F, 0x0990, 0x0993, 0x09A8, 0x09AA, 0x09B0, 0x09B6, 0x09B9,
+        0x09DC, 0x09DD, 0x09DF, 0x09E1, 0x09F0, 0x09F1, 0x0A05, 0x0A0A, 0x0A0F,
+        0x0A10, 0x0A13, 0x0A28, 0x0A2A, 0x0A30, 0x0A32, 0x0A33, 0x0A35, 0x0A36,
+        0x0A38, 0x0A39, 0x0A59, 0x0A5C, 0x0A72, 0x0A74, 0x0A85, 0x0A8B, 0x0A8F,
+        0x0A91, 0x0A93, 0x0AA8, 0x0AAA, 0x0AB0, 0x0AB2, 0x0AB3, 0x0AB5, 0x0AB9,
+        0x0B05, 0x0B0C, 0x0B0F, 0x0B10, 0x0B13, 0x0B28, 0x0B2A, 0x0B30, 0x0B32,
+        0x0B33, 0x0B36, 0x0B39, 0x0B5C, 0x0B5D, 0x0B5F, 0x0B61, 0x0B85, 0x0B8A,
+        0x0B8E, 0x0B90, 0x0B92, 0x0B95, 0x0B99, 0x0B9A, 0x0B9E, 0x0B9F, 0x0BA3,
+        0x0BA4, 0x0BA8, 0x0BAA, 0x0BAE, 0x0BB5, 0x0BB7, 0x0BB9, 0x0C05, 0x0C0C,
+        0x0C0E, 0x0C10, 0x0C12, 0x0C28, 0x0C2A, 0x0C33, 0x0C35, 0x0C39, 0x0C60,
+        0x0C61, 0x0C85, 0x0C8C, 0x0C8E, 0x0C90, 0x0C92, 0x0CA8, 0x0CAA, 0x0CB3,
+        0x0CB5, 0x0CB9, 0x0CE0, 0x0CE1, 0x0D05, 0x0D0C, 0x0D0E, 0x0D10, 0x0D12,
+        0x0D28, 0x0D2A, 0x0D39, 0x0D60, 0x0D61, 0x0E01, 0x0E2E, 0x0E32, 0x0E33,
+        0x0E40, 0x0E45, 0x0E81, 0x0E82, 0x0E87, 0x0E88, 0x0E94, 0x0E97, 0x0E99,
+        0x0E9F, 0x0EA1, 0x0EA3, 0x0EAA, 0x0EAB, 0x0EAD, 0x0EAE, 0x0EB2, 0x0EB3,
+        0x0EC0, 0x0EC4, 0x0F40, 0x0F47, 0x0F49, 0x0F69, 0x10A0, 0x10C5, 0x10D0,
+        0x10F6, 0x1102, 0x1103, 0x1105, 0x1107, 0x110B, 0x110C, 0x110E, 0x1112,
+        0x1154, 0x1155, 0x115F, 0x1161, 0x116D, 0x116E, 0x1172, 0x1173, 0x11AE,
+        0x11AF, 0x11B7, 0x11B8, 0x11BC, 0x11C2, 0x1E00, 0x1E9B, 0x1EA0, 0x1EF9,
+        0x1F00, 0x1F15, 0x1F18, 0x1F1D, 0x1F20, 0x1F45, 0x1F48, 0x1F4D, 0x1F50,
+        0x1F57, 0x1F5F, 0x1F7D, 0x1F80, 0x1FB4, 0x1FB6, 0x1FBC, 0x1FC2, 0x1FC4,
+        0x1FC6, 0x1FCC, 0x1FD0, 0x1FD3, 0x1FD6, 0x1FDB, 0x1FE0, 0x1FEC, 0x1FF2,
+        0x1FF4, 0x1FF6, 0x1FFC, 0x212A, 0x212B, 0x2180, 0x2182, 0x3041, 0x3094,
+        0x30A1, 0x30FA, 0x3105, 0x312C, 0xAC00, 0xD7A3 ];
+
+var IDEOGRAPHIC_CHARS_SINGLE = [ 0x3007 ];
+
+var IDEOGRAPHIC_CHARS_RANGES = [ 0x3021, 0x3029, 0x4E00, 0x9FA5 ];
+
+var DIGIT_CHARS_RANGES = [ 0x0030, 0x0039, 0x0660, 0x0669, 0x06F0, 0x06F9,
+        0x0966, 0x096F, 0x09E6, 0x09EF, 0x0A66, 0x0A6F, 0x0AE6, 0x0AEF, 0x0B66,
+        0x0B6F, 0x0BE7, 0x0BEF, 0x0C66, 0x0C6F, 0x0CE6, 0x0CEF, 0x0D66, 0x0D6F,
+        0x0E50, 0x0E59, 0x0ED0, 0x0ED9, 0x0F20, 0x0F29 ];
+
+function CharsArray(array) {
+    this.array = array;
+}
+
+CharsArray.prototype.testEach = function(namingFunction, checkFunction) {
+    if (this.array != null) {
+        this.array.forEach(function(value) {
+            checkFunction(namingFunction(getCharCode(value)));
+        });
+    }
+};
+
+function CharRangesArray(array) {
+    this.array = array;
+}
+
+CharRangesArray.prototype.testEach = function(namingFunction, checkFunction) {
+    if (this.array != null) {
+        for (var i = 0; i < this.array.length; i += 2) {
+            var rangeStart = getCharCode(this.array[i]);
+            var rangeEnd = getCharCode(this.array[i+1]);
+            for (var c = rangeStart; c <= rangeEnd; c++) {
+                checkFunction(namingFunction(c));
+            }
+        }
+    }
+};
+
+function testCharCode(charCode, namingFunction, checkFunction) {
+    checkFunction(namingFunction(charCode));
+}
+
+var extenderChars = new CharsArray(EXTENDER_CHARS);
+var combiningChars = new CharsArray(COMBINING_CHARS);
+var baseCharsSingle = new CharsArray(BASE_CHARS_SINGLE);
+var baseCharsRanges = new CharRangesArray(BASE_CHARS_RANGES);
+var ideographicCharsSingle = new CharsArray(IDEOGRAPHIC_CHARS_SINGLE);
+var ideographicCharsRanges = new CharRangesArray(IDEOGRAPHIC_CHARS_RANGES);
+var digitCharsRanges = new CharRangesArray(DIGIT_CHARS_RANGES);
+
+// Helper function, which verifies that given custom element name is valid
+function checkValidName(name) {
+    var doc = newHTMLDocument();
+    try {
+        doc.registerElement(name);
+    } catch (e) {
+        assert_unreached('The custom element name \'' + name +
+            '\' should be registered without errors');
+    }
+}
+
+// Helper function, which verifies that given custom element name is invalid
+function checkInvalidName(name) {
+    var doc = newHTMLDocument();
+    assert_throws('SyntaxError', function() {
+            doc.registerElement(name);
+        }, 'Registering invalid custom element name \'' + name + '\' should fail');
+}
+
+// Helper function to extract character code from given object
+// expected input: either charater code or one character long string.
+function getCharCode(c) {
+    if (typeof(c) === 'string') {
+        assert_equals(1, c.length, 'Error in test: input string should be one character long');
+        c = c.charCodeAt(0);
+    }
+    assert_equals('number', typeof(c), 'Error in test: unexpected type for charater code');
+    return c;
+}
+
+var HTML_NAMESPACE = 'http://www.w3.org/1999/xhtml';
+var SVG_NAMESPACE = 'http://www.w3.org/2000/svg';
+
+function newHTMLDocument() {
+    return document.implementation.createHTMLDocument('Test Document');
+}
+
+// Creates new iframe and loads given url into it.
+// Returns reference to created iframe.
+function newIFrame(url) {
+    assert_not_equals(url, null, 'argument url should not be null');
+    var iframe = document.createElement('iframe');
+    iframe.src = url;
+    document.body.appendChild(iframe);
+    return iframe;
+}
+
+// Creates new iframe and loads given url into it.
+// Function f is bound to the iframe's onload event.
+// Function f receives iframe's contentDocument as argument.
+// The iframe is disposed after function f is executed.
+function testInIFrame(url, f, testName, testProps) {
+    var t = async_test(testName, testProps);
+    t.step(function() {
+        var iframe = newIFrame(url);
+        iframe.onload = t.step_func(function() {
+            try {
+                f(iframe.contentDocument);
+                t.done();
+            } finally {
+                iframe.remove();
+            }
+        });
+    });
+}
+
+// Helper function to create a prototype for custom element
+// with predefined callbacks
+function newHTMLElementPrototype() {
+    return newCustomElementPrototype(HTMLElement.prototype);
+}
+
+// Helper function to create a prototype for custom element
+// with predefined callbacks
+function newCustomElementPrototype(parent) {
+    var proto = Object.create(parent);
+    proto.createdCallbackThis = null;
+    proto.createdCallbackCalledCounter = 0;
+
+    proto.attachedCallbackThis = null;
+    proto.attachedCallbackCalledCounter = 0;
+
+    proto.detachedCallbackThis = null;
+    proto.detachedCallbackCalledCounter = 0;
+
+    proto.attributeChangedCallbackThis = null;
+    proto.attributeChangedCallbackCalledCounter = 0;
+    proto.attributeChangedCallbackArgs = null;
+
+    proto.createdCallback = function() {
+        proto.createdCallbackThis = this;
+        proto.createdCallbackCalledCounter++;
+    };
+    proto.attachedCallback = function() {
+        proto.attachedCallbackThis = this;
+        proto.attachedCallbackCalledCounter++;
+    };
+    proto.detachedCallback = function() {
+        proto.detachedCallbackThis = this;
+        proto.detachedCallbackCalledCounter++;
+    };
+    proto.attributeChangedCallback = function(arg1, arg2, arg3) {
+        proto.attributeChangedCallbackThis = this;
+        proto.attributeChangedCallbackCalledCounter++;
+        proto.attributeChangedCallbackArgs = [arg1, arg2, arg3];
+    };
+    return proto;
+}