chromium/src/third_party/blink/web_tests/fast/events/resources/message-port-gc-closed-iframe.html - manifest_repos/chromium_src - Git at Google

 <!DOCTYPE html>
 <script>
 var channel = new MessageChannel();
 channel.port1.start();
 channel.port1.close();
 window.top.postMessage('gcMe', '*');
 </script>
	<!DOCTYPE html>
	<script>
	var channel = new MessageChannel();
	channel.port1.start();
	channel.port1.close();
	window.top.postMessage('gcMe', '*');
	</script>