Add AudioBufferStream.

media/filters/decoder_stream.cc

Index: media/filters/decoder_stream.cc
diff --git a/media/filters/decoder_stream.cc b/media/filters/decoder_stream.cc
index ebda8c00594cc948e3fb528e85b4c1ee2f05d1ff..40ce25453bb3a8f59c3850e6136d27b50217fdd5 100644
--- a/media/filters/decoder_stream.cc
+++ b/media/filters/decoder_stream.cc
@@ -10,6 +10,7 @@
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
+#include "media/base/audio_decoder.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/demuxer_stream.h"
@@ -28,6 +29,11 @@ const char* GetTraceString<DemuxerStream::VIDEO>() {
   return "DecoderStream<VIDEO>::Decode";
 }
 
+template <>
+const char* GetTraceString<DemuxerStream::AUDIO>() {
+  return "DecoderStream<AUDIO>::Decode";
+}
+
 template <DemuxerStream::Type StreamType>
 DecoderStream<StreamType>::DecoderStream(
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
@@ -65,7 +71,6 @@ void DecoderStream<StreamType>::Initialize(DemuxerStream* stream,
   // TODO(xhwang): DecoderSelector only needs a config to select a decoder.
   decoder_selector_->SelectDecoder(
       stream,
-      StatisticsCB(),
       base::Bind(&DecoderStream<StreamType>::OnDecoderSelected,
                  weak_factory_.GetWeakPtr()));
 }
@@ -319,6 +324,7 @@ void DecoderStream<StreamType>::OnDecodeOutputReady(
     return;
   }
 
+  DCHECK(output);
   SatisfyRead(OK, output);
 }
 
@@ -335,6 +341,25 @@ void DecoderStream<StreamType>::ReadFromDemuxerStream() {
                            weak_factory_.GetWeakPtr()));
 }
 
+template <>
+void DecoderStream<DemuxerStream::AUDIO>::ReadFromDemuxerStream() {
+  DVLOG(2) << __FUNCTION__;
+  DCHECK_EQ(state_, STATE_NORMAL) << state_;
+  DCHECK(!read_cb_.is_null());
+  DCHECK(reset_cb_.is_null());
+  DCHECK(stop_cb_.is_null());
+  DCHECK(decoder_);
+
+  if (decoder_->HasQueuedData()) {
+    Decode(NULL);
+  } else {
+    state_ = STATE_PENDING_DEMUXER_READ;
+    stream_->Read(
+        base::Bind(&DecoderStream<DemuxerStream::AUDIO>::OnBufferReady,
+                   weak_factory_.GetWeakPtr()));
+  }
+}
+
 template <DemuxerStream::Type StreamType>
 void DecoderStream<StreamType>::OnBufferReady(
     DemuxerStream::Status status,
@@ -387,12 +412,10 @@ void DecoderStream<StreamType>::ReinitializeDecoder() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK_EQ(state_, STATE_FLUSHING_DECODER) << state_;
 
-  // TODO(rileya): Specialize this for audio, or, better yet, change
-  // DemuxerStream config getters to be templated.
-  DCHECK(stream_->video_decoder_config().IsValidConfig());
+  DCHECK(StreamTraits::GetDecoderConfig(*stream_).IsValidConfig());
   state_ = STATE_REINITIALIZING_DECODER;
   decoder_->Initialize(
-      stream_->video_decoder_config(),
+      StreamTraits::GetDecoderConfig(*stream_),
       base::Bind(&DecoderStream<StreamType>::OnDecoderReinitialized,
                  weak_factory_.GetWeakPtr()));
 }
@@ -492,4 +515,5 @@ void DecoderStream<StreamType>::OnDecoderStopped() {
 }
 
 template class DecoderStream<DemuxerStream::VIDEO>;
+template class DecoderStream<DemuxerStream::AUDIO>;
 }  // namespace media