chromium/third_party/blink/web_tests/http/tests/misc/form-action-using-replaceChild.html

<!DOCTYPE html>
<html>
<body>
<script src="/js-test-resources/js-test.js"></script>
<script>
if (window.testRunner) {
  jsTestIsAsync = true;
}

window.addEventListener('message', function(event) {
  document.write(event.data +
    " The form was rendered correctly." +
    " This test is for bug <a href=\"https://code.google.com/p/chromium/issues/detail?id=388664\">388664</a>\n");
    if (window.testRunner)
      finishJSTest();
}, false);
</script>

<iframe name="f" src="http://127.0.0.1:8000/misc/resources/frame-with-form-action-using-replace-child.html"></iframe>

<script>
window.onload = function() {
  window.frames["f"].document.forms[0].submit();
}
</script>

</body>
</html>