Add support for midstream audio configuration changes.

media/filters/audio_renderer_impl.h

Index: media/filters/audio_renderer_impl.h
diff --git a/media/filters/audio_renderer_impl.h b/media/filters/audio_renderer_impl.h
index 8c0ce80c8823276b696a664b97112028ad247653..f67e6663f623f3a68fdc2f901015873b79d8c345 100644
--- a/media/filters/audio_renderer_impl.h
+++ b/media/filters/audio_renderer_impl.h
@@ -38,8 +38,10 @@ class SingleThreadTaskRunner;
 namespace media {
 
 class AudioBus;
+class AudioBufferConverter;
 class AudioSplicer;
 class DecryptingDemuxerStream;
+class AudioHardwareConfig;
 
 class MEDIA_EXPORT AudioRendererImpl
     : public AudioRenderer,
@@ -57,7 +59,8 @@ class MEDIA_EXPORT AudioRendererImpl
       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
       AudioRendererSink* sink,
       ScopedVector<AudioDecoder> decoders,
-      const SetDecryptorReadyCB& set_decryptor_ready_cb);
+      const SetDecryptorReadyCB& set_decryptor_ready_cb,
+      const AudioHardwareConfig& hardware_params);
   virtual ~AudioRendererImpl();
 
   // AudioRenderer implementation.
@@ -182,6 +185,7 @@ class MEDIA_EXPORT AudioRendererImpl
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   scoped_ptr<AudioSplicer> splicer_;
+  scoped_ptr<AudioBufferConverter> buffer_converter_;
 
   // The sink (destination) for rendered audio. |sink_| must only be accessed
   // on |task_runner_|. |sink_| must never be called under |lock_| or else we
@@ -190,7 +194,10 @@ class MEDIA_EXPORT AudioRendererImpl
 
   AudioBufferStream audio_buffer_stream_;
 
-  // AudioParameters constructed during Initialize().
+  // Interface to the hardware audio params.
+  const AudioHardwareConfig& hardware_config_;
+
+  // Cached copy of hardware params from |hardware_config_|.
   AudioParameters audio_parameters_;
 
   // Callbacks provided during Initialize().