Add breaks in switch statement to fix AppRTCDemo crash

webrtc/examples/objc/AppRTCDemo/ARDSignalingMessage.m

 /*
  *  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 76 matching lines @@
 @implementation ARDSessionDescriptionMessage
 
 @synthesize sessionDescription = _sessionDescription;
 
 - (instancetype)initWithDescription:(RTCSessionDescription *)description {
   ARDSignalingMessageType messageType = kARDSignalingMessageTypeOffer;
   RTCSdpType sdpType = description.type;
   switch (sdpType) {
     case RTCSdpTypeOffer:
       messageType = kARDSignalingMessageTypeOffer;
+      break;
     case RTCSdpTypeAnswer:
       messageType = kARDSignalingMessageTypeAnswer;
+      break;
     case RTCSdpTypePrAnswer:
       NSAssert(NO, @"Unexpected type: %@",
           [RTCSessionDescription stringForType:sdpType]);
+      break;
   }
   if (self = [super initWithType:messageType]) {
     _sessionDescription = description;
   }
   return self;
 }
 
 - (NSData *)JSONData {
   return [_sessionDescription JSONData];
 }
 
 @end
 
 @implementation ARDByeMessage
 
 - (instancetype)init {
   return [super initWithType:kARDSignalingMessageTypeBye];
 }
 
 - (NSData *)JSONData {
   NSDictionary *message = @{
     @"type": @"bye"
   };
   return [NSJSONSerialization dataWithJSONObject:message
                                          options:NSJSONWritingPrettyPrinted
                                            error:NULL];
 }
 
 @end