chromium/third_party/blink/web_tests/external/wpt/speculation-rules/prerender/restriction-request-picture-in-picture.html

<!DOCTYPE html>
<title>Prerendering cannot invoke
       HTMLVideoElement.requestPictureInPicture</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="../resources/utils.js"></script>
<script src="resources/utils.js"></script>

<body>
<script>
setup(() => assertSpeculationRulesIsSupported());

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

  const gotMessage = new Promise(resolve => {
    bc.addEventListener('message', e => {
      resolve(e.data);
    }, {
      once: true
    });
  });

  // Start prerendering a page that attempts to invoke
  // HTMLVideoElement.requestPictureInPicture. This API needs
  // transient activation. So it's expected to fail.
  startPrerendering(`resources/request-picture-in-picture.html?uid=${uid}`);

  const result = await gotMessage;
  assert_equals(result, 'Metadata for the video element are not loaded yet');
}, 'prerendering page cannot invoke' +
   'HTMLVideoElement.requestPictureInPicture');
</script>