Revert of Refactor video capturing code in the render process

content/renderer/media/media_stream_video_capturer_source.h

Index: content/renderer/media/media_stream_video_capturer_source.h
diff --git a/content/renderer/media/media_stream_video_capturer_source.h b/content/renderer/media/media_stream_video_capturer_source.h
index 0fbef5d0dc8d1f543640be7c9ddf790c70be9a06..b719887b50b87c975fa7133bb1731df753d3f3a3 100644
--- a/content/renderer/media/media_stream_video_capturer_source.h
+++ b/content/renderer/media/media_stream_video_capturer_source.h
@@ -7,21 +7,26 @@
 
 #include "base/callback.h"
 #include "base/message_loop/message_loop_proxy.h"
-#include "base/threading/thread_checker.h"
 #include "content/common/media/video_capture.h"
 #include "content/renderer/media/media_stream_video_source.h"
+#include "media/video/capture/video_capture.h"
 
 namespace content {
+
+class VideoCaptureHandle;
 
 // VideoCapturerDelegate is a delegate used by MediaStreamVideoCapturerSource
 // for local video capturer. It uses VideoCaptureImplManager to start / stop
 // and receive I420 frames from Chrome's video capture implementation.
-//
-// This is a render thread only object.
 class CONTENT_EXPORT VideoCapturerDelegate
-    : public base::RefCountedThreadSafe<VideoCapturerDelegate> {
+    : public media::VideoCapture::EventHandler,
+      public base::RefCountedThreadSafe<VideoCapturerDelegate> {
  public:
+  typedef base::Callback<void(const scoped_refptr<media::VideoFrame>&)>
+      NewFrameCallback;
   typedef base::Callback<void(bool running)> StartedCallback;
+  typedef base::Callback<void(const media::VideoCaptureFormats& formats)>
+      SupportedFormatsCallback;
 
   explicit VideoCapturerDelegate(
       const StreamDeviceInfo& device_info);
@@ -33,20 +38,33 @@
   virtual void GetCurrentSupportedFormats(
       int max_requested_width,
       int max_requested_height,
-      const VideoCaptureDeviceFormatsCB& callback);
+      const SupportedFormatsCallback& callback);
 
-  // Starts capturing frames using the resolution in |params|.
+  // Starts deliver frames using the resolution in |params|.
   // |new_frame_callback| is triggered when a new video frame is available.
   // |started_callback| is triggered before the first video frame is received
   // or if the underlying video capturer fails to start.
-  virtual void StartCapture(
+  virtual void StartDeliver(
       const media::VideoCaptureParams& params,
-      const VideoCaptureDeliverFrameCB& new_frame_callback,
+      const NewFrameCallback& new_frame_callback,
       const StartedCallback& started_callback);
 
-  // Stops capturing frames and clears all callbacks including the
+  // Stops deliver frames and clears all callbacks including the
   // SupportedFormatsCallback callback.
-  virtual void StopCapture();
+  virtual void StopDeliver();
+
+ protected:
+  // media::VideoCapture::EventHandler implementation.
+  // These functions are called on the IO thread (same as where
+  // |capture_engine_| runs).
+  virtual void OnStarted(media::VideoCapture* capture) OVERRIDE;
+  virtual void OnStopped(media::VideoCapture* capture) OVERRIDE;
+  virtual void OnPaused(media::VideoCapture* capture) OVERRIDE;
+  virtual void OnError(media::VideoCapture* capture, int error_code) OVERRIDE;
+  virtual void OnRemoved(media::VideoCapture* capture) OVERRIDE;
+  virtual void OnFrameReady(
+      media::VideoCapture* capture,
+      const scoped_refptr<media::VideoFrame>& frame) OVERRIDE;
 
  private:
   friend class base::RefCountedThreadSafe<VideoCapturerDelegate>;
@@ -55,9 +73,9 @@
   virtual ~VideoCapturerDelegate();
 
   void OnFrameReadyOnRenderThread(
-      const scoped_refptr<media::VideoFrame>& frame,
-      const media::VideoCaptureFormat& format);
-  void OnStateUpdateOnRenderThread(VideoCaptureState state);
+      media::VideoCapture* capture,
+      const scoped_refptr<media::VideoFrame>& frame);
+  void OnErrorOnRenderThread(media::VideoCapture* capture);
   void OnDeviceFormatsInUseReceived(const media::VideoCaptureFormats& formats);
   void OnDeviceSupportedFormatsEnumerated(
       const media::VideoCaptureFormats& formats);
@@ -65,31 +83,27 @@
   // The id identifies which video capture device is used for this video
   // capture session.
   media::VideoCaptureSessionId session_id_;
-  base::Closure release_device_cb_;
-  base::Closure stop_capture_cb_;
+  scoped_ptr<VideoCaptureHandle> capture_engine_;
 
   bool is_screen_cast_;
+
+  // Accessed on the thread where StartDeliver is called.
   bool got_first_frame_;
 
-  // |new_frame_callback_| is provided to this class in StartToDeliver and must
-  // be valid until StopDeliver is called.
-  VideoCaptureDeliverFrameCB new_frame_callback_;
-  // |started_callback| is provided to this class in StartToDeliver and must be
+  // |new_frame_callback_| is provided to this class in StartDeliver and must be
+  // valid until StopDeliver is called.
+  NewFrameCallback new_frame_callback_;
+  // |started_callback| is provided to this class in StartDeliver and must be
   // valid until StopDeliver is called.
   StartedCallback started_callback_;
+  // Message loop of the caller of StartDeliver.
+  scoped_refptr<base::MessageLoopProxy> message_loop_proxy_;
 
-  VideoCaptureDeviceFormatsCB source_formats_callback_;
-
-  // Bound to the render thread.
-  base::ThreadChecker thread_checker_;
+  SupportedFormatsCallback source_formats_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCapturerDelegate);
 };
 
-// Owned by WebMediaStreamSource in Blink as a representation of a video
-// stream coming from a camera.
-// This is a render thread only object. All methods must be called on the
-// render thread.
 class CONTENT_EXPORT MediaStreamVideoCapturerSource
     : public MediaStreamVideoSource {
  public: