third_party/web_platform_tests/html/browsers/windows/support-nested-browsing-contexts.html - cobalt - Git at Google

 <body>
 <script>
   var i = document.createElement("iframe");
   i.name = "nested1";
   document.body.appendChild(i);

   window.opener.postMessage({
     "name": window.name,
     "isTop": window.top === window
   }, "*");
 </script>
 </body>
	<body>
	<script>
	var i = document.createElement("iframe");
	i.name = "nested1";
	document.body.appendChild(i);

	window.opener.postMessage({
	"name": window.name,
	"isTop": window.top === window
	}, "*");
	</script>
	</body>