chromium/src/third_party/blink/web_tests/external/wpt/portals/resources/simple-portal-adopts-predecessor.html - manifest_repos/chromium_src - Git at Google

 <!DOCTYPE html>
 <body>
   <script>
     window.portalHost.postMessage("ready");
     onportalactivate = e => document.body.appendChild(e.adoptPredecessor());
   </script>
 </body>
	<!DOCTYPE html>
	<body>
	<script>
	window.portalHost.postMessage("ready");
	onportalactivate = e => document.body.appendChild(e.adoptPredecessor());
	</script>
	</body>