platform/video.videojs/dist/video.es.js
function VideoTrackList() {
    var _this, _ret;

    var tracks = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];
    classCallCheck(this, VideoTrackList);

    var list = void 0;

    // make sure only 1 track is enabled
    // sorted from last index to first index
    for (var i = tracks.length - 1; i >= 0; i--) {
      if (tracks[i].selected) {
        disableOthers$1(tracks, tracks[i]);
        break;
      }
    }

    // IE8 forces us to implement inheritance ourselves
    // as it does not support Object.defineProperty properly
    if (IS_IE8) {
      list = document.createElement('custom');
      for (var prop in TrackList.prototype) {
        if (prop !== 'constructor') {
          list[prop] = TrackList.prototype[prop];
        }
      }
      for (var _prop in VideoTrackList.prototype) {
        if (_prop !== 'constructor') {
          list[_prop] = VideoTrackList.prototype[_prop];
        }
      }
    }

    list = (_this = possibleConstructorReturn(this, _TrackList.call(this, tracks, list)), _this);
    list.changing_ = false;

    /**
     * @member {number} VideoTrackList#selectedIndex
     *         The current index of the selected {@link VideoTrack`}.
     */
    Object.defineProperty(list, 'selectedIndex', {
      get: function get$$1() {
        for (var _i = 0; _i < this.length; _i++) {
          if (this[_i].selected) {
            return _i;
          }
        }
        return -1;
      },
      set: function set$$1() {}
    });

    return _ret = list, possibleConstructorReturn(_this, _ret);
  }
function VideoTrackList() {
    var _this, _ret;

    var tracks = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];
    classCallCheck(this, VideoTrackList);

    var list = void 0;

    // make sure only 1 track is enabled
    // sorted from last index to first index
    for (var i = tracks.length - 1; i >= 0; i--) {
      if (tracks[i].selected) {
        disableOthers$1(tracks, tracks[i]);
        break;
      }
    }

    // IE8 forces us to implement inheritance ourselves
    // as it does not support Object.defineProperty properly
    if (IS_IE8) {
      list = document.createElement('custom');
      for (var prop in TrackList.prototype) {
        if (prop !== 'constructor') {
          list[prop] = TrackList.prototype[prop];
        }
      }
      for (var _prop in VideoTrackList.prototype) {
        if (_prop !== 'constructor') {
          list[_prop] = VideoTrackList.prototype[_prop];
        }
      }
    }

    list = (_this = possibleConstructorReturn(this, _TrackList.call(this, tracks, list)), _this);
    list.changing_ = false;

    /**
     * @member {number} VideoTrackList#selectedIndex
     *         The current index of the selected {@link VideoTrack`}.
     */
    Object.defineProperty(list, 'selectedIndex', {
      get: function get$$1() {
        for (var _i = 0; _i < this.length; _i++) {
          if (this[_i].selected) {
            return _i;
          }
        }
        return -1;
      },
      set: function set$$1() {}
    });

    return _ret = list, possibleConstructorReturn(_this, _ret);
  }
Create an instance of this class.

@param {VideoTrack[]} [tracks=[]]
A list of `VideoTrack` to instantiate the list with.