chromium/src/third_party/blink/web_tests/http/tests/devtools/portals/resources/append-predecessor.html - manifest_repos/chromium_src - Git at Google

 <body>
   <script>
     window.onportalactivate = e => {
       var portal = e.adoptPredecessor();
       document.body.appendChild(portal);
     }
   </script>
 </body>
	<body>
	<script>
	window.onportalactivate = e => {
	var portal = e.adoptPredecessor();
	document.body.appendChild(portal);
	}
	</script>
	</body>