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

media/filters/decrypting_video_decoder.h

 // Copyright (c) 2012 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 MEDIA_FILTERS_DECRYPTING_VIDEO_DECODER_H_
 #define MEDIA_FILTERS_DECRYPTING_VIDEO_DECODER_H_
 
 #include "base/callback.h"
-#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "media/base/decryptor.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/video_decoder.h"
 
 namespace base {
 class MessageLoopProxy;
 }
 
 namespace media {
 
 class DecoderBuffer;
 class Decryptor;
 
 // Decryptor-based VideoDecoder implementation that can decrypt and decode
 // encrypted video buffers and return decrypted and decompressed video frames.
 // All public APIs and callbacks are trampolined to the |message_loop_| so
 // that no locks are required for thread safety.
 //
 // TODO(xhwang): For now, DecryptingVideoDecoder relies on the decryptor to do
 // both decryption and video decoding. Add the path to use the decryptor for
 // decryption only and use other VideoDecoder implementations within
 // DecryptingVideoDecoder for video decoding.
 class MEDIA_EXPORT DecryptingVideoDecoder : public VideoDecoder {
  public:
   DecryptingVideoDecoder(
       const scoped_refptr<base::MessageLoopProxy>& message_loop,
       const SetDecryptorReadyCB& set_decryptor_ready_cb);
+  virtual ~DecryptingVideoDecoder();
 
   // VideoDecoder implementation.
   virtual void Initialize(const scoped_refptr<DemuxerStream>& stream,
                           const PipelineStatusCB& status_cb,
                           const StatisticsCB& statistics_cb) OVERRIDE;
   virtual void Read(const ReadCB& read_cb) OVERRIDE;
   virtual void Reset(const base::Closure& closure) OVERRIDE;
   virtual void Stop(const base::Closure& closure) OVERRIDE;
 
- protected:
-  virtual ~DecryptingVideoDecoder();
-
  private:
   // For a detailed state diagram please see this link: http://goo.gl/8jAok
   // TODO(xhwang): Add a ASCII state diagram in this file after this class
   // stabilizes.
   enum State {
     kUninitialized = 0,
     kDecryptorRequested,
     kPendingDecoderInit,
     kIdle,
     kPendingConfigChange,
@@ skipping 30 matching lines @@
   // added.
   void OnKeyAdded();
 
   // Reset decoder and call |reset_cb_|.
   void DoReset();
 
   // Free decoder resources and call |stop_cb_|.
   void DoStop();
 
   scoped_refptr<base::MessageLoopProxy> message_loop_;
+  base::WeakPtrFactory<DecryptingVideoDecoder> weak_factory_;
+  base::WeakPtr<DecryptingVideoDecoder> weak_this_;
 
   State state_;
 
   PipelineStatusCB init_cb_;
   StatisticsCB statistics_cb_;
   ReadCB read_cb_;
   base::Closure reset_cb_;
 
   // Pointer to the demuxer stream that will feed us compressed buffers.
   scoped_refptr<DemuxerStream> demuxer_stream_;
@@ skipping 16 matching lines @@
   // A unique ID to trace Decryptor::DecryptAndDecodeVideo() call and the
   // matching DecryptCB call (in DoDeliverFrame()).
   uint32 trace_id_;
 
   DISALLOW_COPY_AND_ASSIGN(DecryptingVideoDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_DECRYPTING_VIDEO_DECODER_H_