Fix for scenario where m-line is revived after being set to port 0.

talk/app/webrtc/rtpsender.h

 /*
  * libjingle
  * Copyright 2015 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 67 matching lines @@
 
   // ObserverInterface implementation
   void OnChanged() override;
 
   // RtpSenderInterface implementation
   bool SetTrack(MediaStreamTrackInterface* track) override;
   rtc::scoped_refptr<MediaStreamTrackInterface> track() const override {
     return track_.get();
   }
 
+  cricket::MediaType media_type() const override {
+    return cricket::MEDIA_TYPE_AUDIO;
+  }
+
   std::string id() const override { return id_; }
 
   void Stop() override;
 
+  void Reconfigure() override;
+
  private:
-  void Reconfigure();
-
   std::string id_;
   rtc::scoped_refptr<AudioTrackInterface> track_;
   uint32_t ssrc_;
   AudioProviderInterface* provider_;
   bool cached_track_enabled_;
 
   // Used to pass the data callback from the |track_| to the other end of
   // cricket::AudioRenderer.
   rtc::scoped_ptr<LocalAudioSinkAdapter> sink_adapter_;
 };
 
 class VideoRtpSender : public ObserverInterface,
                        public rtc::RefCountedObject<RtpSenderInterface> {
  public:
   VideoRtpSender(VideoTrackInterface* track,
                  uint32_t ssrc,
                  VideoProviderInterface* provider);
 
   virtual ~VideoRtpSender();
 
   // ObserverInterface implementation
   void OnChanged() override;
 
   // RtpSenderInterface implementation
   bool SetTrack(MediaStreamTrackInterface* track) override;
   rtc::scoped_refptr<MediaStreamTrackInterface> track() const override {
     return track_.get();
   }
 
+  cricket::MediaType media_type() const override {
+    return cricket::MEDIA_TYPE_VIDEO;
+  }
+
   std::string id() const override { return id_; }
 
   void Stop() override;
 
+  // Calls SetCaptureDevice and SetVideoSend.
+  void Reconfigure() override;
+
  private:
-  void Reconfigure();
+  // Only calls SetVideoSend.

[pthatcher1, 2015/11/11 00:45:02]

Perhaps this would be more clear as "Only calls VideoChannel::SetVideoSend"

Saying "SetVideoSend calls SetVideoSend" makes it sound recursive.

[Taylor Brandstetter, 2015/11/11 01:33:30]

Done.

+  void SetVideoSend();
 
   std::string id_;
   rtc::scoped_refptr<VideoTrackInterface> track_;
   uint32_t ssrc_;
   VideoProviderInterface* provider_;
   bool cached_track_enabled_;
 };
 
 }  // namespace webrtc
 
 #endif  // TALK_APP_WEBRTC_RTPSENDER_H_