Use scoped_refptr for On(Add|Remove)Stream and OnDataChannel.

webrtc/examples/peerconnection/client/conductor.cc

 /*
  *  Copyright 2012 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 138 matching lines @@
     if (main_wnd_->current_ui() != MainWindow::STREAMING)
       main_wnd_->SwitchToStreamingUI();
   }
 }
 
 //
 // PeerConnectionObserver implementation.
 //
 
 // Called when a remote stream is added
-void Conductor::OnAddStream(webrtc::MediaStreamInterface* stream) {
+void Conductor::OnAddStream(
+    rtc::scoped_refptr<webrtc::MediaStreamInterface> stream) {
   LOG(INFO) << __FUNCTION__ << " " << stream->label();
-
-  stream->AddRef();
-  main_wnd_->QueueUIThreadCallback(NEW_STREAM_ADDED,
-                                   stream);
+  main_wnd_->QueueUIThreadCallback(NEW_STREAM_ADDED, stream.release());

[tkchin_webrtc, 2016/05/12 17:50:22]

I haven't seen scoped_refptr used like this before, but I think it works.

[Taylor Brandstetter, 2016/05/12 17:52:34]

Yep; ".release()" is basically what you want to do when converting from a refptr
to a raw pointer which will be Released manually.

 }
 
-void Conductor::OnRemoveStream(webrtc::MediaStreamInterface* stream) {
+void Conductor::OnRemoveStream(
+    rtc::scoped_refptr<webrtc::MediaStreamInterface> stream) {
   LOG(INFO) << __FUNCTION__ << " " << stream->label();
-  stream->AddRef();
-  main_wnd_->QueueUIThreadCallback(STREAM_REMOVED,
-                                   stream);
+  main_wnd_->QueueUIThreadCallback(STREAM_REMOVED, stream.release());
 }
 
 void Conductor::OnIceCandidate(const webrtc::IceCandidateInterface* candidate) {
   LOG(INFO) << __FUNCTION__ << " " << candidate->sdp_mline_index();
   // For loopback test. To save some connecting delay.
   if (loopback_) {
     if (!peer_connection_->AddIceCandidate(candidate)) {
       LOG(WARNING) << "Failed to apply the received candidate";
     }
     return;
@@ skipping 358 matching lines @@
 }
 
 void Conductor::OnFailure(const std::string& error) {
     LOG(LERROR) << error;
 }
 
 void Conductor::SendMessage(const std::string& json_object) {
   std::string* msg = new std::string(json_object);
   main_wnd_->QueueUIThreadCallback(SEND_MESSAGE_TO_PEER, msg);
 }