title: Remotely load <track> element in HTML video
body: <p>I can't seem to load remote VTT files into an html5 video player (in ReactJS, using video-react v 0.11.2 (<a href="https://github.com/video-react/video-react" rel="nofollow noreferrer">https://github.com/video-react/video-react</a>)</p>
  
  <pre><code>&lt;track
      kind="subtitles"
      label="English subtitles"
      src={api.makeFileURL(this.props.chapterPart.VideoFile[0].subtitles, this.props.user.id)}
      srcLang="en"
      default={true}
  /&gt;
  </code></pre>
  
  <p>This doesn't work.  The makeFileURL method creates a url to the vtt file.  Example: <a href="http://localhost:3000/api/file/download/5b1932c7f4717028c0b5d711-1529538217239-nicks.vtt?access_token=Q4tBHTC36Rumijnvsb9QruNlQJ5EX1mQPBLD86LHFHfJU3ttXOzCdOJBeqIj6xP9" rel="nofollow noreferrer">http://localhost:3000/api/file/download/5b1932c7f4717028c0b5d711-1529538217239-nicks.vtt?access_token=Q4tBHTC36Rumijnvsb9QruNlQJ5EX1mQPBLD86LHFHfJU3ttXOzCdOJBeqIj6xP9</a></p>
  
  <p>When I access that file in my browser, I can see the file, and the mimetype is VTT.  When I include the file into my project, and load it locally into the track element, everything works fine.</p>
  
  <pre><code>&lt;track
      kind="subtitles"
      label="English subtitles"
      src="/static/media/5b1932c7f4717028c0b5d711-1529538217239-nicks.vtt"
      srcLang="en"
      default={true}
  /&gt;
  </code></pre>
  
  <p>Thought it was a cross origin issue.  So I added crossOrigin="true" to the Player element, which in turn passes that prop to the html5 video element, but as I watch the network tab in FF or chrome, I never see the file being requested when it's a remote url.  When it's a local url, the file shows up in the network tab and everything works as it should.</p>
  
  <p>There are no errors, just, the text track won't load remote files.</p>