Convert WebAudio file handlers to use AudioBus.

media/filters/audio_file_reader.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.
 
 #ifndef MEDIA_FILTERS_AUDIO_FILE_READER_H_
 #define MEDIA_FILTERS_AUDIO_FILE_READER_H_
 
 #include <vector>
 #include "media/filters/ffmpeg_glue.h"
 
-struct AVCodec;
 struct AVCodecContext;
 struct AVFormatContext;
 
 namespace base { class TimeDelta; }
 
 namespace media {
 
+class AudioBus;
 class FFmpegURLProtocol;
 
 class MEDIA_EXPORT AudioFileReader {
  public:
   // Audio file data will be read using the given protocol.
   // The AudioFileReader does not take ownership of |protocol| and
   // simply maintains a weak reference to it.
   explicit AudioFileReader(FFmpegURLProtocol* protocol);
   virtual ~AudioFileReader();
 
   // Open() reads the audio data format so that the sample_rate(),
   // channels(), duration(), and number_of_frames() methods can be called.
   // It returns |true| on success.
   bool Open();
   void Close();
 
-  // After a call to Open(), reads |number_of_frames| into |audio_data|.
+  // After a call to Open(), attempts to fully fill |audio_bus| with decoded
+  // audio data.  Any unfilled frames will be zeroed out.
   // |audio_data| must be of the same size as channels().
   // The audio data will be decoded as floating-point linear PCM with
   // a nominal range of -1.0 -> +1.0.
   // Returns |true| on success.
-  bool Read(const std::vector<float*>& audio_data, size_t number_of_frames);
+  bool Read(AudioBus* audio_bus);
 
   // These methods can be called once Open() has been called.
   int channels() const;
   int sample_rate() const;
   base::TimeDelta duration() const;
   int64 number_of_frames() const;
 
  private:
   FFmpegURLProtocol* protocol_;
   AVFormatContext* format_context_;
   AVCodecContext* codec_context_;
-  AVCodec* codec_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioFileReader);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_AUDIO_FILE_READER_H_