Update iOS AppRTCDemo to use level controller.

webrtc/examples/objc/AppRTCDemo/ARDAppClient.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.
  */
 
@@ skipping 47 matching lines @@
 @property(nonatomic, weak) id<ARDAppClientDelegate> delegate;
 
 // Convenience constructor since all expected use cases will need a delegate
 // in order to receive remote tracks.
 - (instancetype)initWithDelegate:(id<ARDAppClientDelegate>)delegate;
 
 // Establishes a connection with the AppRTC servers for the given room id.
 // If |isLoopback| is true, the call will connect to itself.
 // If |isAudioOnly| is true, video will be disabled for the call.
 // If |shouldMakeAecDump| is true, an aecdump will be created for the call.
+// If |shouldUseLevelControl| is true, the level controller will be used
+// in the call.
 - (void)connectToRoomWithId:(NSString *)roomId
                  isLoopback:(BOOL)isLoopback
                 isAudioOnly:(BOOL)isAudioOnly
-          shouldMakeAecDump:(BOOL)shouldMakeAecDump;
+          shouldMakeAecDump:(BOOL)shouldMakeAecDump
+      shouldUseLevelControl:(BOOL)shouldUseLevelControl;
 
 // Disconnects from the AppRTC servers and any connected clients.
 - (void)disconnect;
 
 @end