remoteCall_(targetName, methodName, ...varArgs) {
    goog.asserts.assert(targetName == 'video' || targetName == 'player',
        'Unexpected target name');
    this.sendMessage_({
      'type': 'call',
      'targetName': targetName,
      'methodName': methodName,
      'args': varArgs,
    });
  }
@param {string} targetName
@param {string} methodName
@param {...*} varArgs
@private