Refactor VideoDestinationHandler to implement MediaStreamVideoSource.

content/renderer/media/video_destination_handler.h

-// Copyright (c) 2013 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_VIDEO_DESTINATION_HANDLER_H_
-#define CONTENT_RENDERER_MEDIA_VIDEO_DESTINATION_HANDLER_H_
-
-#include <string>
-#include <vector>
-
-#include "base/compiler_specific.h"
-#include "base/synchronization/lock.h"
-#include "content/common/content_export.h"
-#include "third_party/libjingle/source/talk/media/base/videocapturer.h"
-
-namespace content {
-
-class MediaStreamDependencyFactory;
-class MediaStreamRegistryInterface;
-class PPB_ImageData_Impl;
-
-// Interface used by the effects pepper plugin to output the processed frame
-// to the video track.
-class CONTENT_EXPORT FrameWriterInterface {
- public:
-  // The ownership of the |image_data| deosn't transfer. So the implementation
-  // of this interface should make a copy of the |image_data| before return.
-  virtual void PutFrame(PPB_ImageData_Impl* image_data,
-                        int64 time_stamp_ns) = 0;
-  virtual ~FrameWriterInterface() {}
-};
-
-// PpFrameWriter implements cricket::VideoCapturer so that it can be used in
-// the native video track's video source. It also implements
-// FrameWriterInterface, which will be used by the effects pepper plugin to
-// inject the processed frame.
-class CONTENT_EXPORT PpFrameWriter
-    : public NON_EXPORTED_BASE(cricket::VideoCapturer),
-      public FrameWriterInterface {
- public:
-  PpFrameWriter();
-  virtual ~PpFrameWriter();
-
-  // cricket::VideoCapturer implementation.
-  // These methods are accessed from a libJingle worker thread.
-  virtual cricket::CaptureState Start(
-      const cricket::VideoFormat& capture_format) OVERRIDE;
-  virtual void Stop() OVERRIDE;
-  virtual bool IsRunning() OVERRIDE;
-  virtual bool GetPreferredFourccs(std::vector<uint32>* fourccs) OVERRIDE;
-  virtual bool GetBestCaptureFormat(const cricket::VideoFormat& desired,
-                                    cricket::VideoFormat* best_format) OVERRIDE;
-  virtual bool IsScreencast() const OVERRIDE;
-
-  // FrameWriterInterface implementation.
-  // This method will be called by the Pepper host from render thread.
-  virtual void PutFrame(PPB_ImageData_Impl* image_data,
-                        int64 time_stamp_ns) OVERRIDE;
-
- private:
-  bool started_;
-  // |lock_| is used to protect |started_| which will be accessed from different
-  // threads - libjingle worker thread and render thread.
-  base::Lock lock_;
-
-  DISALLOW_COPY_AND_ASSIGN(PpFrameWriter);
-};
-
-// VideoDestinationHandler is a glue class between the webrtc MediaStream and
-// the effects pepper plugin host.
-class CONTENT_EXPORT VideoDestinationHandler {
- public:
-  // Instantiates and adds a new video track to the MediaStream specified by
-  // |url|. Returns a handler for delivering frames to the new video track as
-  // |frame_writer|.
-  // If |factory| is NULL the MediaStreamDependencyFactory owned by
-  // RenderThreadImpl::current() will be used.
-  // If |registry| is NULL the global blink::WebMediaStreamRegistry will be
-  // used to look up the media stream.
-  // The caller of the function takes the ownership of |frame_writer|.
-  // Returns true on success and false on failure.
-  static bool Open(MediaStreamDependencyFactory* factory,
-                   MediaStreamRegistryInterface* registry,
-                   const std::string& url,
-                   FrameWriterInterface** frame_writer);
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(VideoDestinationHandler);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_MEDIA_VIDEO_DESTINATION_HANDLER_H_
-