Add VideoTrackSource implementation.

webrtc/api/mediastreaminterface.h

 /*
  *  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 121 matching lines @@
   // But it should not be used for starting or stopping capturing.
   // TODO(perkj): We are currently trying to replace all internal use of
   // cricket::VideoCapturer with rtc::VideoSourceInterface. Once that
   // refactoring is done,
   // remove this method.
   virtual cricket::VideoCapturer* GetVideoCapturer() = 0;
 
   virtual void Stop() = 0;
   virtual void Restart() = 0;
 
-  virtual const cricket::VideoOptions* options() const = 0;
+  virtual bool is_screencast() const = 0;
+  virtual bool needs_denoising() const = 0;

[pthatcher1, 2016/03/08 21:27:31]

Can you put a comment in here like:

// Indicates that parameters suitable for screencasts should be automatically
applied to RtpSenders.  
// TODO: Remove these once all known applications have moved to explicitly
setting suitable parameters for screencasts and dont' need this implicit
behavior.

and

// Indicates that the encoder should denoise the video before encoding it.  
// TODO: Remove this once denoising is done by the source, and not by the
encoder.

[perkj_webrtc, 2016/03/08 22:23:57]

Done.

 
  protected:
   virtual ~VideoTrackSourceInterface() {}
 };
 
 class VideoTrackInterface
     : public MediaStreamTrackInterface,
       public rtc::VideoSourceInterface<cricket::VideoFrame> {
  public:
   // AddRenderer and RemoveRenderer are for backwards compatibility
@@ skipping 154 matching lines @@
   virtual bool RemoveTrack(AudioTrackInterface* track) = 0;
   virtual bool RemoveTrack(VideoTrackInterface* track) = 0;
 
  protected:
   virtual ~MediaStreamInterface() {}
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_MEDIASTREAMINTERFACE_H_