Fold DecoderStream::Stop() into the dtor.

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 2e29a9e82110adce8bccd546adcb3992a1323247..76690b5f1188729132e3221765db113510154253 100644
--- a/media/filters/audio_renderer_impl.h
+++ b/media/filters/audio_renderer_impl.h
@@ -22,6 +22,7 @@
 #include <deque>
 
 #include "base/gtest_prod_util.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "media/base/audio_decoder.h"
@@ -203,7 +204,7 @@ class MEDIA_EXPORT AudioRendererImpl
   // may deadlock between |task_runner_| and the audio callback thread.
   scoped_refptr<media::AudioRendererSink> sink_;
 
-  AudioBufferStream audio_buffer_stream_;
+  scoped_ptr<AudioBufferStream> audio_buffer_stream_;
 
   // Interface to the hardware audio params.
   const AudioHardwareConfig* const hardware_config_;