RTCPeerConnectionInterface.mm createNativeConfiguration and other clean-up.

talk/app/webrtc/objc/RTCPeerConnection.mm

Index: talk/app/webrtc/objc/RTCPeerConnection.mm
diff --git a/talk/app/webrtc/objc/RTCPeerConnection.mm b/talk/app/webrtc/objc/RTCPeerConnection.mm
index da092c80269b6c378bdb2aaf6f0a726bf70d7aa8..2491cf7c97bc1b0f74eb0b4a8ae4b349bd8606e2 100644
--- a/talk/app/webrtc/objc/RTCPeerConnection.mm
+++ b/talk/app/webrtc/objc/RTCPeerConnection.mm
@@ -211,8 +211,12 @@ class RTCStatsObserver : public StatsObserver {
 }
 
 - (BOOL)setConfiguration:(RTCConfiguration *)configuration {
-  return self.peerConnection->SetConfiguration(
-      configuration.nativeConfiguration);
+  std::unique_ptr<webrtc::PeerConnectionInterface::RTCConfiguration> config(
+      [configuration createNativeConfiguration]);
+  if (!config) {
+    return NO;
+  }
+  return self.peerConnection->SetConfiguration(*config);
 }
 
 - (RTCSessionDescription*)localDescription {