third_party/blink/web_tests/external/wpt/dom/nodes/query-target-in-load-event.html

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<iframe></iframe>

<script>
  let test = async_test('document.querySelector(":target") must work when called in the window.load event');
  let iframe = document.querySelector("iframe");
  window.addEventListener("message", test.step_func_done(event => {
    assert_equals(event.data, "PASS");
  }));
  iframe.src = "./query-target-in-load-event.part.html#target";
</script>