Import Cobalt 21.master.0.253153
diff --git a/src/third_party/web_platform_tests/intersection-observer/edge-inclusive-intersection.html b/src/third_party/web_platform_tests/intersection-observer/edge-inclusive-intersection.html
new file mode 100644
index 0000000..b73c407
--- /dev/null
+++ b/src/third_party/web_platform_tests/intersection-observer/edge-inclusive-intersection.html
@@ -0,0 +1,67 @@
+<!DOCTYPE html>
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="./resources/intersection-observer-test-utils.js"></script>
+
+<style>
+pre, #log {
+ position: absolute;
+ top: 0;
+ left: 200px;
+}
+#root {
+ width: 200px;
+ height: 200px;
+ overflow: visible;
+}
+#target {
+ background-color: green;
+}
+</style>
+
+<div id="root">
+ <div id="target" style="width: 100px; height: 100px; transform: translateY(250px)"></div>
+</div>
+
+<script>
+var entries = [];
+
+runTestCycle(function() {
+ var root = document.getElementById('root');
+ assert_true(!!root, "root element exists.");
+ var target = document.getElementById('target');
+ assert_true(!!target, "target element exists.");
+ var observer = new IntersectionObserver(function(changes) {
+ entries = entries.concat(changes);
+ }, { root: root });
+ observer.observe(target);
+ entries = entries.concat(observer.takeRecords());
+ assert_equals(entries.length, 0, "No initial notifications.");
+ runTestCycle(step0, "First rAF.");
+}, "IntersectionObserver should detect and report edge-adjacent and zero-area intersections.");
+
+function step0() {
+ runTestCycle(step1, "Set transform=translateY(200px) on target.");
+ checkLastEntry(entries, 0, [8, 108, 258, 358, 0, 0, 0, 0, 8, 208, 8, 208, false]);
+ target.style.transform = "translateY(200px)";
+}
+
+function step1() {
+ runTestCycle(step2, "Set transform=translateY(201px) on target.");
+ checkLastEntry(entries, 1, [8, 108, 208, 308, 8, 108, 208, 208, 8, 208, 8, 208, true]);
+ target.style.transform = "translateY(201px)";
+}
+
+function step2() {
+ runTestCycle(step3, "Set transform=translateY(185px) on target.");
+ checkLastEntry(entries, 2);
+ target.style.height = "0px";
+ target.style.width = "300px";
+ target.style.transform = "translateY(185px)";
+}
+
+function step3() {
+ checkLastEntry(entries, 3, [8, 308, 193, 193, 8, 208, 193, 193, 8, 208, 8, 208, true]);
+}
+</script>
