RTCPeerConnectionInterface.mm createNativeConfiguration and other clean-up.

talk/app/webrtc/objc/RTCPeerConnectionFactory.mm

 /*
  * libjingle
  * Copyright 2013 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 81 matching lines @@
     NSAssert(_nativeFactory, @"Failed to initialize PeerConnectionFactory!");
     // Uncomment to get sensitive logs emitted (to stderr or logcat).
     // rtc::LogMessage::LogToDebug(rtc::LS_SENSITIVE);
   }
   return self;
 }
 
 - (RTCPeerConnection *)peerConnectionWithConfiguration:(RTCConfiguration *)configuration
                                            constraints:(RTCMediaConstraints *)constraints
                                               delegate:(id<RTCPeerConnectionDelegate>)delegate {
+  std::unique_ptr<webrtc::PeerConnectionInterface::RTCConfiguration> config(
+      [configuration createNativeConfiguration]);
+  if (!config) {
+    return nil;
+  }
   return [[RTCPeerConnection alloc] initWithFactory:self.nativeFactory.get()
-                                             config:configuration.nativeConfiguration
+                                             config:*config
                                         constraints:constraints.constraints
                                            delegate:delegate];
 }
 
 - (RTCPeerConnection*)
     peerConnectionWithICEServers:(NSArray*)servers
                      constraints:(RTCMediaConstraints*)constraints
                         delegate:(id<RTCPeerConnectionDelegate>)delegate {
   webrtc::PeerConnectionInterface::IceServers iceServers;
   for (RTCICEServer* server in servers) {
@@ skipping 31 matching lines @@
   return [[RTCVideoTrack alloc] initWithMediaTrack:track];
 }
 
 - (RTCAudioTrack*)audioTrackWithID:(NSString*)audioId {
   rtc::scoped_refptr<webrtc::AudioTrackInterface> track =
       self.nativeFactory->CreateAudioTrack([audioId UTF8String], NULL);
   return [[RTCAudioTrack alloc] initWithMediaTrack:track];
 }
 
 @end