Loopback mode for AppRTCDemo on iOS.

webrtc/examples/objc/AppRTCDemo/ARDRoomServerClient.h

 /*
  *  Copyright 2014 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #import <Foundation/Foundation.h>
 
 @class ARDJoinResponse;
 @class ARDMessageResponse;
 @class ARDSignalingMessage;
 
 @protocol ARDRoomServerClient <NSObject>
 
 - (void)joinRoomWithRoomId:(NSString *)roomId
+                isLoopback:(BOOL)isLoopback
          completionHandler:(void (^)(ARDJoinResponse *response,
                                      NSError *error))completionHandler;
 
 - (void)sendMessage:(ARDSignalingMessage *)message
             forRoomId:(NSString *)roomId
              clientId:(NSString *)clientId
     completionHandler:(void (^)(ARDMessageResponse *response,
                                 NSError *error))completionHandler;
 
 - (void)leaveRoomWithRoomId:(NSString *)roomId
                    clientId:(NSString *)clientId
           completionHandler:(void (^)(NSError *error))completionHandler;
 
 @end