third_party/web_platform_tests/page-visibility/test_read_only.html - cobalt - Git at Google

 <!DOCTYPE html>
 <html>
     <head>
         <meta charset="utf-8" />
         <title>Page Visibility API is Read Only</title>

         <script src="/resources/testharness.js"></script>
         <script src="/resources/testharnessreport.js"></script>
         <script type="text/javascript" src="resources/pagevistestharness.js"></script>

         <script type="text/javascript">
             setup({ explicit_done: true });
             function onload_test()
             {
                 //check for feature definition first before attempting to overwrite
                 pv_test();

                 //Check document.hidden
                 document.hidden = "new value";
                 test_true(document.hidden !== "new value", 'document.hidden is read only.');

                 //Check document.visibilityState
                 document.visibilityState = "new value";
                 test_true(document.visibilityState !== "new value",
                                 "document.visibilityState is read only.");

                 done();
             }
         </script>
     </head>
     <body onload="onload_test();">
         <h1>Description</h1>
         <p>This test validates that the Page Visibility attributes are read only.</p>

         <div id="log"></div>
     </body>
 </html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8" />
	<title>Page Visibility API is Read Only</title>

	<script src="/resources/testharness.js"></script>
	<script src="/resources/testharnessreport.js"></script>
	<script type="text/javascript" src="resources/pagevistestharness.js"></script>

	<script type="text/javascript">
	setup({ explicit_done: true });
	function onload_test()
	{
	//check for feature definition first before attempting to overwrite
	pv_test();

	//Check document.hidden
	document.hidden = "new value";
	test_true(document.hidden !== "new value", 'document.hidden is read only.');

	//Check document.visibilityState
	document.visibilityState = "new value";
	test_true(document.visibilityState !== "new value",
	"document.visibilityState is read only.");

	done();
	}
	</script>
	</head>
	<body onload="onload_test();">
	<h1>Description</h1>
	<p>This test validates that the Page Visibility attributes are read only.</p>

	<div id="log"></div>
	</body>
	</html>