LayoutTests/http/tests/eventloop/resources/promise-from-cross-origin-detached-iframe-subframe.html - WebKit - Git at Google

 <!DOCTYPE html>
 <html>
 <body>
 <script>
 frame = document.createElement('iframe');
 document.body.appendChild(frame);
 frame.contentWindow.Promise.resolve("test").then(() => {
      parent.postMessage("Promise was resolved", "*");
 });
 </script>
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<body>
	<script>
	frame = document.createElement('iframe');
	document.body.appendChild(frame);
	frame.contentWindow.Promise.resolve("test").then(() => {
	parent.postMessage("Promise was resolved", "*");
	});
	</script>
	</body>
	</html>