Remove reference counting from media::Demuxer and friends.

media/base/video_decoder.h

Index: media/base/video_decoder.h
diff --git a/media/base/video_decoder.h b/media/base/video_decoder.h
index 46116456316dcccfc45fca40e48175406ff6ee33..5d20d1ac9ad083a2d5699d14ee5f770d92a5185e 100644
--- a/media/base/video_decoder.h
+++ b/media/base/video_decoder.h
@@ -34,7 +34,7 @@ class MEDIA_EXPORT VideoDecoder {
   // Note:
   // 1) No VideoDecoder calls should be made before |status_cb| is executed.
   // 2) DemuxerStream should not be accessed after the VideoDecoder is stopped.
-  virtual void Initialize(const scoped_refptr<DemuxerStream>& stream,
+  virtual void Initialize(DemuxerStream* stream,
                           const PipelineStatusCB& status_cb,
                           const StatisticsCB& statistics_cb) = 0;