Remove reference counting from media::DemuxerStream and friends.

media/filters/opus_audio_decoder.cc

Index: media/filters/opus_audio_decoder.cc
diff --git a/media/filters/opus_audio_decoder.cc b/media/filters/opus_audio_decoder.cc
index 82436b190c1c26e2b7a908ac545e16d208203810..548289d193fa1aae6fbf4319edc8b36acfe7cf5e 100644
--- a/media/filters/opus_audio_decoder.cc
+++ b/media/filters/opus_audio_decoder.cc
@@ -244,6 +244,7 @@ OpusAudioDecoder::OpusAudioDecoder(
     const scoped_refptr<base::MessageLoopProxy>& message_loop)
     : message_loop_(message_loop),
       weak_factory_(this),
+      demuxer_stream_(NULL),
       opus_decoder_(NULL),
       bits_per_channel_(0),
       channel_layout_(CHANNEL_LAYOUT_NONE),
@@ -254,7 +255,7 @@ OpusAudioDecoder::OpusAudioDecoder(
 }
 
 void OpusAudioDecoder::Initialize(
-    const scoped_refptr<DemuxerStream>& stream,
+    DemuxerStream* stream,
     const PipelineStatusCB& status_cb,
     const StatisticsCB& statistics_cb) {
   DCHECK(message_loop_->BelongsToCurrentThread());