Reland: Remove reference counting from media::VideoDecoder and friends.

media/filters/ffmpeg_video_decoder.h

Index: media/filters/ffmpeg_video_decoder.h
diff --git a/media/filters/ffmpeg_video_decoder.h b/media/filters/ffmpeg_video_decoder.h
index 4c6629e2f8ef2dcc73d1476579c1a827777cbfdc..de8381460a887ee398d2596d259d6e208f392694 100644
--- a/media/filters/ffmpeg_video_decoder.h
+++ b/media/filters/ffmpeg_video_decoder.h
@@ -8,7 +8,7 @@
 #include <list>
 
 #include "base/callback.h"
-#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/video_decoder.h"
 
@@ -27,6 +27,7 @@ class MEDIA_EXPORT FFmpegVideoDecoder : public VideoDecoder {
  public:
   explicit FFmpegVideoDecoder(
       const scoped_refptr<base::MessageLoopProxy>& message_loop);
+  virtual ~FFmpegVideoDecoder();
 
   // VideoDecoder implementation.
   virtual void Initialize(const scoped_refptr<DemuxerStream>& stream,
@@ -41,9 +42,6 @@ class MEDIA_EXPORT FFmpegVideoDecoder : public VideoDecoder {
   // documentation inside FFmpeg.
   int GetVideoBuffer(AVCodecContext *codec_context, AVFrame* frame);
 
- protected:
-  virtual ~FFmpegVideoDecoder();
-
  private:
   enum DecoderState {
     kUninitialized,
@@ -74,6 +72,8 @@ class MEDIA_EXPORT FFmpegVideoDecoder : public VideoDecoder {
   void DoReset();
 
   scoped_refptr<base::MessageLoopProxy> message_loop_;
+  base::WeakPtrFactory<FFmpegVideoDecoder> weak_factory_;
+  base::WeakPtr<FFmpegVideoDecoder> weak_this_;
 
   DecoderState state_;