<!DOCTYPE html> <html class="reftest-wait"> <body> <iframe id="foo" src="data:text/html,<body bgcolor='red'>FAIL</body>"></iframe> <script type="text/javascript"> // Globals var foo = document.getElementById('foo'); var win = foo.contentWindow; // Start the chain of execution when iframe's window loads win.onload = iframeWindowLoaded; function iframeWindowLoaded() { setTimeout("tweak()", 0); } function tweak() { win.location ="data:text/html,<body bgcolor='lime'>PASS</body>"; foo.onload = snapshot; } function snapshot() { document.documentElement.className = ''; } </script> </body> </html>