chromium/third_party/blink/web_tests/wpt_internal/prerender/activate-from-iframe.html

<!DOCTYPE html>
<title>Activate a prerendered page from iframe via window.parent.location</title>
<meta name="timeout" content="long">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/common/utils.js"></script>
<script src="/speculation-rules/prerender/resources/utils.js"></script>
<script>

promise_test(async t => {
  const uid = token();
  const channel = new PrerenderChannel('result-channel', uid);
  const messageQueue = new BroadcastMessageQueue(channel);
  t.add_cleanup(_ => channel.close());

  const url = `resources/activate-from-iframe.html?mode=triggering&uid=${uid}`;
  window.open(url, '_blank', 'noopener');

  const messages = [];
  messages.push(await messageQueue.nextMessage());
  messages.push(await messageQueue.nextMessage());
  // Sort them for the assertion. These messages come from separate frames
  // (prerendered frame and navigated frame), so the message order is not
  // guaranteed.
  messages.sort();

  assert_array_equals(
      messages,
      ['attempting prerender activation', 'loaded from scratch']);
}, `Navigation on the main frame initiated by window opened by an ` +
    `iframe opening via window.parent.location should not activate a ` +
    `prerendered page`);

</script>