platform/video.videojs/dist/video.es.js
function loadTrack(src, track) {
  var opts = {
    uri: src
  };
  var crossOrigin = isCrossOrigin(src);

  if (crossOrigin) {
    opts.cors = crossOrigin;
  }

  xhr(opts, bind(this, function (err, response, responseBody) {
    if (err) {
      return log$1.error(err, response);
    }

    track.loaded_ = true;

    // Make sure that vttjs has loaded, otherwise, wait till it finished loading
    // NOTE: this is only used for the alt/video.novtt.js build
    if (typeof window.WebVTT !== 'function') {
      if (track.tech_) {
        var loadHandler = function loadHandler() {
          return parseCues(responseBody, track);
        };

        track.tech_.on('vttjsloaded', loadHandler);
        track.tech_.on('vttjserror', function () {
          log$1.error('vttjs failed to load, stopping trying to process ' + track.src);
          track.tech_.off('vttjsloaded', loadHandler);
        });
      }
    } else {
      parseCues(responseBody, track);
    }
  }));
}
function loadTrack(src, track) {
  var opts = {
    uri: src
  };
  var crossOrigin = isCrossOrigin(src);

  if (crossOrigin) {
    opts.cors = crossOrigin;
  }

  xhr(opts, bind(this, function (err, response, responseBody) {
    if (err) {
      return log$1.error(err, response);
    }

    track.loaded_ = true;

    // Make sure that vttjs has loaded, otherwise, wait till it finished loading
    // NOTE: this is only used for the alt/video.novtt.js build
    if (typeof window.WebVTT !== 'function') {
      if (track.tech_) {
        var loadHandler = function loadHandler() {
          return parseCues(responseBody, track);
        };

        track.tech_.on('vttjsloaded', loadHandler);
        track.tech_.on('vttjserror', function () {
          log$1.error('vttjs failed to load, stopping trying to process ' + track.src);
          track.tech_.off('vttjsloaded', loadHandler);
        });
      }
    } else {
      parseCues(responseBody, track);
    }
  }));
}
Load a `TextTrack` from a specifed url.

@param {string} src
Url to load track from.

@param {TextTrack} track
Track to add cues to. Comes from the content at the end of `url`.

@private