Add support for midstream audio configuration changes.

media/filters/opus_audio_decoder.h

Index: media/filters/opus_audio_decoder.h
diff --git a/media/filters/opus_audio_decoder.h b/media/filters/opus_audio_decoder.h
index 16ec982002ef96d7d5895d52290feee77995c831..150abf9a8224eb4ded9594ac4f348f9f2b84251d 100644
--- a/media/filters/opus_audio_decoder.h
+++ b/media/filters/opus_audio_decoder.h
@@ -36,9 +36,6 @@ class MEDIA_EXPORT OpusAudioDecoder : public AudioDecoder {
                           const PipelineStatusCB& status_cb) OVERRIDE;
   virtual void Decode(const scoped_refptr<DecoderBuffer>& buffer,
                       const DecodeCB& decode_cb) OVERRIDE;
-  virtual int bits_per_channel() OVERRIDE;
-  virtual ChannelLayout channel_layout() OVERRIDE;
-  virtual int samples_per_second() OVERRIDE;
   virtual void Reset(const base::Closure& closure) OVERRIDE;
   virtual void Stop(const base::Closure& closure) OVERRIDE;
 
@@ -64,12 +61,6 @@ class MEDIA_EXPORT OpusAudioDecoder : public AudioDecoder {
   AudioDecoderConfig config_;
   OpusMSDecoder* opus_decoder_;
 
-  // Decoded audio format.
-  ChannelLayout channel_layout_;
-  int samples_per_second_;
-  const SampleFormat sample_format_;
-  const int bits_per_channel_;
-
   // Used for computing output timestamps.
   scoped_ptr<AudioTimestampHelper> output_timestamp_helper_;
   base::TimeDelta last_input_timestamp_;