Add video codec setting to AppRTCMobile on iOS.

webrtc/examples/objc/AppRTCMobile/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 26 matching lines @@
 @synthesize videoCallView = _videoCallView;
 @synthesize delegate = _delegate;
 
 - (instancetype)initForRoom:(NSString *)room
                  isLoopback:(BOOL)isLoopback
                 isAudioOnly:(BOOL)isAudioOnly
           shouldMakeAecDump:(BOOL)shouldMakeAecDump
       shouldUseLevelControl:(BOOL)shouldUseLevelControl
                    delegate:(id<ARDVideoCallViewControllerDelegate>)delegate {
   if (self = [super init]) {
+    ARDSettingsModel *settingsModel = [[ARDSettingsModel alloc] init];
+    NSString* videoCodec = [settingsModel currentVideoCodecSettingFromStore];
     _delegate = delegate;
-    _client = [[ARDAppClient alloc] initWithDelegate:self];
-    ARDSettingsModel *settingsModel = [[ARDSettingsModel alloc] init];
+    _client = [[ARDAppClient alloc] initWithDelegate:self
+                                    preferVideoCodec:videoCodec];
     RTCMediaConstraints *cameraConstraints = [[RTCMediaConstraints alloc]
         initWithMandatoryConstraints:nil
                  optionalConstraints:[settingsModel
                                          currentMediaConstraintFromStoreAsRTCDictionary]];
     [_client setMaxBitrate:[settingsModel currentMaxBitrateSettingFromStore]];
     [_client setCameraConstraints:cameraConstraints];
     [_client connectToRoomWithId:room
                       isLoopback:isLoopback
                      isAudioOnly:isAudioOnly
                shouldMakeAecDump:shouldMakeAecDump
@@ skipping 161 matching lines @@
 - (void)showAlertWithMessage:(NSString*)message {
   UIAlertView* alertView = [[UIAlertView alloc] initWithTitle:nil
                                                       message:message
                                                      delegate:nil
                                             cancelButtonTitle:@"OK"
                                             otherButtonTitles:nil];
   [alertView show];
 }
 
 @end