Fix deprecated methods in AppRTCMobile.

webrtc/examples/objc/AppRTCMobile/ios/ARDMainViewController.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 237 matching lines @@
 
 - (void)restartAudioPlayerIfNeeded {
   if (_mainView.isAudioLoopPlaying && !self.presentedViewController) {
     RTCLog(@"Starting audio loop due to WebRTC end.");
     [self configureAudioSession];
     [_audioPlayer play];
   }
 }
 
 - (void)showAlertWithMessage:(NSString*)message {
-  UIAlertView* alertView = [[UIAlertView alloc] initWithTitle:nil
-                                                      message:message
-                                                     delegate:nil
-                                            cancelButtonTitle:@"OK"
-                                            otherButtonTitles:nil];
-  [alertView show];
+  UIAlertController *alert =
+      [UIAlertController alertControllerWithTitle:nil
+                                          message:message
+                                   preferredStyle:UIAlertControllerStyleAlert];
+
+  UIAlertAction *defaultAction = [UIAlertAction actionWithTitle:@"OK"
+                                                          style:UIAlertActionStyleDefault
+                                                        handler:^(UIAlertAction *action){
+                                                        }];
+
+  [alert addAction:defaultAction];
+  [self presentViewController:alert animated:YES completion:nil];
 }
 
 @end