Implement a source for remote video tracks.

content/renderer/media/media_stream_video_source.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_SOURCE_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_SOURCE_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
@@ skipping 46 matching lines @@
   // Puts |track| in the registered tracks list.
   void AddTrack(MediaStreamVideoTrack* track,
                 const blink::WebMediaConstraints& constraints,
                 const ConstraintsCallback& callback);
   void RemoveTrack(MediaStreamVideoTrack* track);
 
   // TODO(ronghuawu): Remove webrtc::VideoSourceInterface from the public
   // interface of this class.
   // This creates a VideoSourceInterface implementation if it does not already
   // exist.
-  webrtc::VideoSourceInterface* GetAdapter();
+  virtual webrtc::VideoSourceInterface* GetAdapter();
 
   // Return true if |name| is a constraint supported by MediaStreamVideoSource.
   static bool IsConstraintSupported(const std::string& name);
 
   // Constraint keys used by a video source.
   // Specified by draft-alvestrand-constraints-resolution-00b
   static const char kMinAspectRatio[];  // minAspectRatio
   static const char kMaxAspectRatio[];  // maxAspectRatio
   static const char kMaxWidth[];  // maxWidth
   static const char kMinWidth[];  // minWidthOnCaptureFormats
@@ skipping 45 matching lines @@
   // method has been called, MediaStreamVideoSource may be deleted.
   virtual void StopSourceImpl() = 0;
 
   enum State {
     NEW,
     RETRIEVING_CAPABILITIES,
     STARTING,
     STARTED,
     ENDED
   };
-  State state() { return state_; }
+  State state() const { return state_; }
 
  private:
   // Creates a webrtc::VideoSourceInterface used by libjingle.
   void InitAdapter();
 
   // Finds the first constraints in |requested_constraints_| that can be
   // fulfilled. |best_format| is set to the video resolution that can be
   // fulfilled. |frame_output_size| is the requested frame size after cropping.
   // |resulting_constraints| is set to the found constraints in
   // |requested_constraints_|.
@@ skipping 34 matching lines @@
   MediaStreamDependencyFactory* factory_;
   scoped_refptr<webrtc::VideoSourceInterface> adapter_;
   WebRtcVideoCapturerAdapter* capture_adapter_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamVideoSource);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_SOURCE_H_