Introduce AudioDecoderConfig to migrate away from GetAVStream().

media/filters/adaptive_demuxer.h

 // Copyright (c) 2011 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.
 
 // Implements a Demuxer that can switch among different data sources mid-stream.
 // Uses FFmpegDemuxer under the covers, so see the caveats at the top of
 // ffmpeg_demuxer.h.
 
 #ifndef MEDIA_FILTERS_ADAPTIVE_DEMUXER_H_
 #define MEDIA_FILTERS_ADAPTIVE_DEMUXER_H_
@@ skipping 52 matching lines @@
   // referenced pointer must not be NULL. The SeekFunction parameter
   // provides a way to seek |streams_[index]| to a specific time.
   void ChangeCurrentStream(int index, const SeekFunction& seek_function,
                            const PipelineStatusCB& cb);
 
   // DemuxerStream methods.
   virtual void Read(const ReadCallback& read_callback);
   virtual Type type();
   virtual void EnableBitstreamConverter();
   virtual AVStream* GetAVStream();
+  virtual const AudioDecoderConfig& audio_decoder_config();
 
  private:
   // Returns a pointer to the current stream.
   DemuxerStream* current_stream();
 
   // DEBUG_MODE-only CHECK that the data members are in a reasonable state.
   void DCheckSanity();
 
   void OnReadDone(Buffer* buffer);
 
@@ skipping 177 matching lines @@
 };
 
 // See AdaptiveDemuxerFactory's class-level comment for |url|'s format.
 MEDIA_EXPORT bool ParseAdaptiveUrl(
     const std::string& url, int* audio_index, int* video_index,
     std::vector<std::string>* urls);
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_ADAPTIVE_DEMUXER_H_