Move audio decoder initialization to AudioRendererImpl.

media/base/filter_collection.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_BASE_FILTER_COLLECTION_H_
 #define MEDIA_BASE_FILTER_COLLECTION_H_
 
 #include <list>
 
 #include "base/memory/ref_counted.h"
 #include "media/base/media_export.h"
 
 namespace media {
 
 class AudioDecoder;
 class AudioRenderer;
 class Demuxer;
 class VideoDecoder;
 class VideoRenderer;
 
 // Represents a set of uninitialized demuxer and audio/video decoders and
 // renderers. Used to start a Pipeline object for media playback.
 //
 // TODO(scherkus): Replace FilterCollection with something sensible, see
 // http://crbug.com/110800
 class MEDIA_EXPORT FilterCollection {
  public:
+  typedef std::list<scoped_refptr<AudioDecoder> > AudioDecoderList;
   typedef std::list<scoped_refptr<VideoDecoder> > VideoDecoderList;
 
   FilterCollection();
   ~FilterCollection();
 
   // Demuxer accessor methods.
   void SetDemuxer(const scoped_refptr<Demuxer>& demuxer);
   const scoped_refptr<Demuxer>& GetDemuxer();
 
   // Adds a filter to the collection.
   void AddAudioDecoder(AudioDecoder* audio_decoder);
   void AddAudioRenderer(AudioRenderer* audio_renderer);
   void AddVideoRenderer(VideoRenderer* video_renderer);
 
   // Remove remaining filters.
   void Clear();
 
   // Selects a filter of the specified type from the collection.
   // If the required filter cannot be found, NULL is returned.
   // If a filter is returned it is removed from the collection.
   // Filters are selected in FIFO order.
-  void SelectAudioDecoder(scoped_refptr<AudioDecoder>* out);
   void SelectAudioRenderer(scoped_refptr<AudioRenderer>* out);
   void SelectVideoRenderer(scoped_refptr<VideoRenderer>* out);
 
+  AudioDecoderList* GetAudioDecoders();

[acolwell GONE FROM CHROMIUM, 2012/10/15 21:00:07]

Do we really want a list here? We don't have more than one audio decoder.

[xhwang, 2012/10/15 22:52:23]

The reason I work on this CL now is to be prepared for adding another audio
decoder: DecryptingAudioDecoder.

   VideoDecoderList* GetVideoDecoders();
 
  private:
   scoped_refptr<Demuxer> demuxer_;
-  std::list<scoped_refptr<AudioDecoder> > audio_decoders_;
+  AudioDecoderList audio_decoders_;
   VideoDecoderList video_decoders_;
   std::list<scoped_refptr<AudioRenderer> > audio_renderers_;
   std::list<scoped_refptr<VideoRenderer> > video_renderers_;
 
   DISALLOW_COPY_AND_ASSIGN(FilterCollection);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_FILTER_COLLECTION_H_