third_party/blink/web_tests/external/wpt/signed-exchange/resources/inner-url.html - chromium/src - Git at Google

 <!DOCTYPE html>
 <title>Content of fallback URL</title>
 <script>
 window.addEventListener('message', (event) => {
   event.data.port.postMessage({
       location: document.location.href,
       referrer: document.referrer,
       is_fallback: true});
 }, false);
 </script>
	<!DOCTYPE html>
	<title>Content of fallback URL</title>
	<script>
	window.addEventListener('message', (event) => {
	event.data.port.postMessage({
	location: document.location.href,
	referrer: document.referrer,
	is_fallback: true});
	}, false);
	</script>