chromium/third_party/blink/web_tests/http/tests/subresource_filter/overlay_popup_ad/overlay-popup-ad-video-midrolls.html

<!DOCTYPE html>
<html>
<head>
<style>
video {
  position: fixed;
  width: 100vw;
  height: 100vh;
}
iframe {
  position: fixed;
  margin-left: 25vw;
  width: 50vw;
  height: 100vh;
  border: 0px;
}
p {
  position: fixed;
}
div.bottom {
  position: absolute;
  top: 10000px;
  left: 0px;
  width: 1px;
  height: 1px;
}
</style>

<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="../resources/overlay-interstitial-ad-testharness.js"></script>
</head>
<body marginwidth="0" marginheight="0">

<!-- To trigger the first contentful paint at the very start -->
<p>some content</p>

<!-- The content video. -->
<video controls></video>

<!-- To be positioned further down in the main page to make the page scrollable -->
<div class="bottom"></div>

<script>
promise_test(async function(t) {
  // After 1500ms, force a layout update so that the interstitial detector
  // would have been aware of the first meaningful paint (hadn't we skipped
  // the detection in fullscreen video scenario).
  await timeout(1500);
  await forceLayoutUpdate();

  // Create the overlay pop-up ad.
  appendAdFrameTo(document.body);

  // Force a layout update, so that the interstitial detector would have
  // been aware of the overlay candidate (hadn't we skipped the detection in
  // fullscreen video scenario).
  await forceLayoutUpdate();

  // Hide the pop-up.
  document.getElementsByTagName('iframe')[0].style.display = 'none';

  // Force a layout update, so that the interstitial detector would have
  // been aware of the overlay candidate's dismissal (hadn't we skipped the
  // detection in fullscreen video scenario).
  await forceLayoutUpdate();

  // Expect that the use counter kOverlayPopupAd is not recorded, as we
  // skipped all previous detection due to there was a fullscreen video
  // element.
  assert_false(internals.isUseCounted(document, kOverlayPopupAd));
}, "Test that we will skip the overlay-popup-ad detection if there's a dominant video element in the page.");

</script>
</body>
</html>