document-write-in-iframe-onload.html

<html>
<head>
<script>
    if (window.testRunner)
        testRunner.dumpAsText();
</script>
</head>
<body>
FAIL: Text from the top of the origin document should not be visible after the onload event.<br>
<iframe onload="document.open();document.write('PASS');document.close();"></iframe>
FAIL: Text from the bottom of the origin document should not be visible after the onload event.<br>
</body>
</html>

chromium/third_party/blink/web_tests/fast/frames/document-write-in-iframe-onload.html