Added the API to create an RTCRtpSender to the Objective C wrapper.

webrtc/sdk/objc/Framework/Classes/RTCPeerConnection.mm

Index: webrtc/sdk/objc/Framework/Classes/RTCPeerConnection.mm
diff --git a/webrtc/sdk/objc/Framework/Classes/RTCPeerConnection.mm b/webrtc/sdk/objc/Framework/Classes/RTCPeerConnection.mm
index e8fa4c9a564f9c43ecd2be65d163bd008f4e84c6..80b85102e0bc2061639017af0fd2a605b8830b49 100644
--- a/webrtc/sdk/objc/Framework/Classes/RTCPeerConnection.mm
+++ b/webrtc/sdk/objc/Framework/Classes/RTCPeerConnection.mm
@@ -311,6 +311,16 @@ void PeerConnectionDelegateAdapter::OnIceCandidate(
   _peerConnection->SetRemoteDescription(observer, sdp.nativeDescription);
 }
 
+- (RTCRtpSender *)senderWithKind:(NSString *)kind
+                        streamId:(NSString *)streamId {
+  rtc::scoped_refptr<webrtc::RtpSenderInterface> nativeSender(
+      _peerConnection->CreateSender([NSString stdStringForString:kind],

[tkchin_webrtc, 2016/04/27 20:22:20]

nit: use locals for the stdStrings to make this more readable

[skvlad, 2016/04/27 23:00:58]

Done.

+          [NSString stdStringForString:streamId]));
+  return nativeSender ?
+      [[RTCRtpSender alloc] initWithNativeRtpSender:nativeSender]
+      : nil;
+}
+
 - (NSArray<RTCRtpSender *> *)senders {
   std::vector<rtc::scoped_refptr<webrtc::RtpSenderInterface>> nativeSenders(
       _peerConnection->GetSenders());