chromium/third_party/blink/web_tests/media/controls/accessibility-time-element.html

<!DOCTYPE html>
<html lang="en-US">
<title>Media Controls: time elements accessibility test</title>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="../media-controls.js"></script>
<video controls></video>
<script>
async_test(t => {
  var video = document.querySelector('video');
  video.src = '../content/test.ogv';

  enableTestMode(video);

  var current_time = currentTimeElement(video);
  var remaining_time = timeRemainingElement(video);

  assert_not_equals(current_time, null);
  assert_not_equals(remaining_time, null);

  assert_equals(current_time.ariaHidden, 'true');
  assert_equals(remaining_time.ariaHidden, 'true');

video.oncanplaythrough = t.step_func_done(_ => {
  assert_equals(current_time.ariaHidden, 'true');
  assert_equals(remaining_time.ariaHidden, 'true');

    video.currentTime = 1;
    video.onseeked = t.step_func(_ => {
      assert_equals(current_time.ariaHidden, 'true');
      assert_equals(remaining_time.ariaHidden, 'true');
    });
  });
});
</script>
</html>