chrome/test/data/downloads/message.html - chromium/src - Git at Google

 <!doctype html>
 <script>
 if (window.parent === window)
   document.title = "Loaded as main frame";
 else
   window.parent.postMessage('Loaded as iframe', '*');
 </script>
	<!doctype html>
	<script>
	if (window.parent === window)
	document.title = "Loaded as main frame";
	else
	window.parent.postMessage('Loaded as iframe', '*');
	</script>