chromium/third_party/blink/web_tests/media/controls/buttons-after-reset.html

<!DOCTYPE html>
<html>
<title>Test that resetting the controls after load is a no-op.</title>
<script src="../media-controls.js"></script>
<script src="../../resources/run-after-layout-and-paint.js"></script>
<video controls width=400>
  <track kind=subtitles src=fake-en-sub.vtt srclang=en label=English>
  <track kind=subtitles src=fake-fr-sub.vtt srclang=fr label=French>
</video>
<script>
  if (window.testRunner)
    testRunner.waitUntilDone();

  var video = document.querySelector('video');
  enableTestMode(video);
  video.src = '../content/test.ogv';
  video.addEventListener('loadedmetadata', () => {
    video.controls = false;
    runAfterLayoutAndPaint(() => {
      video.controls = true;

      runAfterLayoutAndPaint(() => {
        testRunner.notifyDone();
      });
    });
  });
</script>
</html>