Use the right mirroring state when switching cameras in AppRTCDemo.

webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallViewController.m

 /*
  *  Copyright 2015 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 170 matching lines @@
     [self.presentingViewController dismissViewControllerAnimated:YES
                                                       completion:nil];
   }
 }
 
 - (void)switchCamera {
   RTCVideoSource* source = self.localVideoTrack.source;
   if ([source isKindOfClass:[RTCAVFoundationVideoSource class]]) {
     RTCAVFoundationVideoSource* avSource = (RTCAVFoundationVideoSource*)source;
     avSource.useBackCamera = !avSource.useBackCamera;
-    _videoCallView.localVideoView.transform = avSource.useBackCamera ?
-        CGAffineTransformIdentity : CGAffineTransformMakeScale(-1, 1);
   }
 }
 
 - (NSString *)statusTextForState:(RTCIceConnectionState)state {
   switch (state) {
     case RTCIceConnectionStateNew:
     case RTCIceConnectionStateChecking:
       return @"Connecting...";
     case RTCIceConnectionStateConnected:
     case RTCIceConnectionStateCompleted:
     case RTCIceConnectionStateFailed:
     case RTCIceConnectionStateDisconnected:
     case RTCIceConnectionStateClosed:
     case RTCIceConnectionStateMax:
       return nil;
   }
 }
 
 - (void)showAlertWithMessage:(NSString*)message {
   UIAlertView* alertView = [[UIAlertView alloc] initWithTitle:nil
                                                       message:message
                                                      delegate:nil
                                             cancelButtonTitle:@"OK"
                                             otherButtonTitles:nil];
   [alertView show];
 }
 
 @end