chromium/src/third_party/blink/web_tests/media/controls/keynav-preventdefault.html

<DOCTYPE html>
  <title>Test media controls video keyboard navigation with preventDefault()</title>
  <script src="../../resources/testharness.js"></script>
  <script src="../../resources/testharnessreport.js"></script>
  <script src="../media-controls.js"></script>
  <script>
  test(_ => {
    assert_true('eventSender' in window);
  }, 'eventSender required');

  async_test(function(t) {
      var video = document.createElement('video');
      video.src = "../content/test.ogv";
      video.controls = true;
      assert_equals(video.volume, 1);
      assert_equals(video.currentTime, 0);

      video.addEventListener('keydown', e => { e.preventDefault() });
      video.addEventListener('keypress', e => { e.preventDefault() });
      video.addEventListener('keyup', e => { e.preventDefault() });

      video.oncanplaythrough = t.step_func_done(function() {
        // Focus the video.
        video.focus();

        // 'Enter' does not play the video.
        eventSender.keyDown("Enter");
        assert_true(video.paused);

        // 'Down' does not reduce volume.
        eventSender.keyDown("ArrowDown");
        assert_equals(video.volume, 1);

        // 'Space' also does not pauses/plays the video.
        eventSender.keyDown(" ");
        assert_true(video.paused);

        var cur = video.currentTime;

        // 'Right' does not scrub the timeline forward.
        eventSender.keyDown("ArrowRight");
        assert_equals(video.currentTime, cur);

        // 'End' does not set the timeline to end.
        eventSender.keyDown("End");
        assert_equals(video.currentTime, cur);
      });

      document.body.appendChild(video);
  });
  </script>