chromium/third_party/blink/web_tests/fast/parser/document-write-onload-ordering.html

<script>
if (window.testRunner)
    testRunner.dumpAsText();
</script>
<iframe onload="alert(0);document.write('<p>PASS<iframe onload=&quot;alert(1);document.write(\'<p><iframe onload=alert(3)></iframe>\');alert(4);&quot;></iframe><iframe onload=alert(2)></iframe>');alert(5);document.close();"></iframe>