Remove reference counting from media::DemuxerStream and friends.

media/filters/decrypting_audio_decoder.cc

Index: media/filters/decrypting_audio_decoder.cc
diff --git a/media/filters/decrypting_audio_decoder.cc b/media/filters/decrypting_audio_decoder.cc
index 8f29f0f83e7ac999cff1d13dbdb4f6c550dc75e0..7b0fbea5795802e093f9280d7d499d09af240cd6 100644
--- a/media/filters/decrypting_audio_decoder.cc
+++ b/media/filters/decrypting_audio_decoder.cc
@@ -39,6 +39,7 @@ DecryptingAudioDecoder::DecryptingAudioDecoder(
     : message_loop_(message_loop),
       weak_factory_(this),
       state_(kUninitialized),
+      demuxer_stream_(NULL),
       set_decryptor_ready_cb_(set_decryptor_ready_cb),
       decryptor_(NULL),
       key_added_while_decode_pending_(false),
@@ -51,7 +52,7 @@ DecryptingAudioDecoder::DecryptingAudioDecoder(
 }
 
 void DecryptingAudioDecoder::Initialize(
-    const scoped_refptr<DemuxerStream>& stream,
+    DemuxerStream* stream,
     const PipelineStatusCB& status_cb,
     const StatisticsCB& statistics_cb) {
   DVLOG(2) << "Initialize()";