<!DOCTYPE html>
<title>HTMLTrackElement 'src' attribute changed, load pending, 'error' handler mutates</title>
<link rel="help" href="https://html.spec.whatwg.org/multipage/media.html#start-the-track-processing-model">
<link rel="help" href="https://crbug.com/1374341">
<video></video>
<script>
  const video = document.querySelector('video');
  video.style.visibility = 'collapse';
  video.setAttribute('crossorigin', 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa');
  const track = document.createElement('track');
  track.src = 'x';
  track.track.mode = 'hidden';
  video.appendChild(track);
  track.onerror = () => {
    for (let i = 0; i < 10; ++i)
      video.setAttribute('foo' + i, 'bar');
  };
  setTimeout(() => {
    track.src = 'y';
  }, 0);
</script>
