Use new RTCCameraVideoCapturer in AppRTCMobile.

webrtc/examples/objc/AppRTCMobile/ios/ARDVideoCallView.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 13 matching lines @@
 static CGFloat const kStatusBarHeight = 20;
 
 @interface ARDVideoCallView () <RTCEAGLVideoViewDelegate>
 @end
 
 @implementation ARDVideoCallView {
   UIButton *_routeChangeButton;
   UIButton *_cameraSwitchButton;
   UIButton *_hangupButton;
   CGSize _remoteVideoSize;
-  BOOL _useRearCamera;
 }
 
 @synthesize statusLabel = _statusLabel;
 @synthesize localVideoView = _localVideoView;
 @synthesize remoteVideoView = _remoteVideoView;
 @synthesize statsView = _statsView;
 @synthesize delegate = _delegate;
 
 - (instancetype)initWithFrame:(CGRect)frame {
   if (self = [super initWithFrame:frame]) {
@@ skipping 150 matching lines @@
 
 - (void)onHangup:(id)sender {
   [_delegate videoCallViewDidHangup:self];
 }
 
 - (void)didTripleTap:(UITapGestureRecognizer *)recognizer {
   [_delegate videoCallViewDidEnableStats:self];
 }
 
 @end