onRemoteEvent_(targetName, event) {
    goog.asserts.assert(this.sender_.isCasting(),
        'Should only receive remote events while casting');
    if (!this.sender_.isCasting()) {
      // Ignore any unexpected remote events.
      return;
    }

    if (targetName == 'video') {
      this.videoEventTarget_.dispatchEvent(event);
    } else if (targetName == 'player') {
      if (event.type == shaka.util.FakeEvent.EventName.Unloading) {
        this.resetExternalTracks();
      }
      this.playerEventTarget_.dispatchEvent(event);
    }
  }
@param {string} targetName
@param {!shaka.util.FakeEvent} event
@private