third_party/blink/web_tests/external/wpt/device-bound-session-credentials/url_fetcher.html - chromium/src - Git at Google

 <!DOCTYPE html>
 <meta charset="utf-8">
 <body>
   <script>
     'use strict';

     window.addEventListener("message", async (event) => {
       const req = event.data;
       const response = await fetch(req.url, req.fetchParams);
       event.source.postMessage(response.status, "*");
     });
   </script>
 </body>
	<!DOCTYPE html>
	<meta charset="utf-8">
	<body>
	<script>
	'use strict';

	window.addEventListener("message", async (event) => {
	const req = event.data;
	const response = await fetch(req.url, req.fetchParams);
	event.source.postMessage(response.status, "*");
	});
	</script>
	</body>