chromium/third_party/blink/web_tests/media/video-positive-start-time.html

<!DOCTYPE html>
<title>video with a postive start time</title>
<script src="../resources/testharness.js"></script>
<script src="../resources/testharnessreport.js"></script>
<video></video>
<script>
async_test(function(t) {
  var video = document.querySelector('video');

  video.onloadeddata = t.step_func_done(function() {
    assert_equals(video.currentTime, 3, 'currentTime');

    // FIXME: Once Chrome correctly exposes seekable ranges for media with
    // positive start times, verify video.seekable.start(0) here.
  });

  video.src = 'resources/test-positive-start-time.webm';
});
</script>