Remove AudioDecoder from the Filter heirarchy.

media/base/filter_collection.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/base/filter_collection.h"
 
 #include "base/logging.h"
+#include "media/base/audio_decoder.h"
 
 namespace media {
 
 FilterCollection::FilterCollection() {}
 
 FilterCollection::~FilterCollection() {}
 
 void FilterCollection::SetDemuxerFactory(scoped_ptr<DemuxerFactory> factory) {
   DCHECK(factory.get());
   demuxer_factory_ = factory.Pass();
 }
 
 DemuxerFactory* FilterCollection::GetDemuxerFactory() {
   return demuxer_factory_.get();
 }
 
 void FilterCollection::AddVideoDecoder(VideoDecoder* filter) {
   AddFilter(VIDEO_DECODER, filter);
 }
 
-void FilterCollection::AddAudioDecoder(AudioDecoder* filter) {
-  AddFilter(AUDIO_DECODER, filter);
+void FilterCollection::AddAudioDecoder(AudioDecoder* audio_decoder) {
+  audio_decoders_.push_back(audio_decoder);
 }
 
 void FilterCollection::AddVideoRenderer(VideoRenderer* filter) {
   AddFilter(VIDEO_RENDERER, filter);
 }
 
 void FilterCollection::AddAudioRenderer(AudioRenderer* filter) {
   AddFilter(AUDIO_RENDERER, filter);
 }
 
 bool FilterCollection::IsEmpty() const {
-  return filters_.empty();
+  return filters_.empty() && audio_decoders_.empty();
 }
 
 void FilterCollection::Clear() {
   filters_.clear();
+  audio_decoders_.clear();
 }
 
 void FilterCollection::SelectVideoDecoder(
     scoped_refptr<VideoDecoder>* filter_out) {
   SelectFilter<VIDEO_DECODER>(filter_out);
 }
 
-void FilterCollection::SelectAudioDecoder(
-    scoped_refptr<AudioDecoder>* filter_out) {
-  SelectFilter<AUDIO_DECODER>(filter_out);
+void FilterCollection::SelectAudioDecoder(scoped_refptr<AudioDecoder>* out) {
+  if (audio_decoders_.empty()) {
+    *out = NULL;
+    return;
+  }
+  *out = audio_decoders_.front();
+  audio_decoders_.pop_front();
 }
 
 void FilterCollection::SelectVideoRenderer(
     scoped_refptr<VideoRenderer>* filter_out) {
   SelectFilter<VIDEO_RENDERER>(filter_out);
 }
 
 void FilterCollection::SelectAudioRenderer(
     scoped_refptr<AudioRenderer>* filter_out) {
   SelectFilter<AUDIO_RENDERER>(filter_out);
@@ skipping 22 matching lines @@
     ++it;
   }
 
   if (it != filters_.end()) {
     *filter_out = it->second.get();
     filters_.erase(it);
   }
 }
 
 }  // namespace media