Revert of [chromecast] Pass media task runner to MediaPipelineBackendManager.

chromecast/media/audio/cast_audio_manager.cc

 // Copyright 2015 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 "chromecast/media/audio/cast_audio_manager.h"
 
 #include <algorithm>
 #include <string>
 
 #include "chromecast/media/audio/cast_audio_output_stream.h"
+#include "chromecast/media/base/media_message_loop.h"
 #include "chromecast/media/cma/backend/media_pipeline_backend_manager.h"
+#include "chromecast/public/cast_media_shlib.h"
+#include "chromecast/public/media/media_pipeline_backend.h"
 
 namespace {
 // TODO(alokp): Query the preferred value from media backend.
 const int kDefaultSampleRate = 48000;
 
 // Define bounds for the output buffer size (in frames).
 // Note: These values are copied from AudioManagerPulse implementation.
 // TODO(alokp): Query the preferred value from media backend.
 static const int kMinimumOutputBufferSize = 512;
 static const int kMaximumOutputBufferSize = 8192;
 static const int kDefaultOutputBufferSize = 2048;
 }  // namespace
 
 namespace chromecast {
 namespace media {
 
-CastAudioManager::CastAudioManager(::media::AudioLogFactory* audio_log_factory,
-                                   MediaPipelineBackendManager* backend_manager)
-    : AudioManagerBase(audio_log_factory), backend_manager_(backend_manager) {
-}
+CastAudioManager::CastAudioManager(::media::AudioLogFactory* audio_log_factory)
+    : AudioManagerBase(audio_log_factory) {}
 
 CastAudioManager::~CastAudioManager() {
   Shutdown();
 }
 
 bool CastAudioManager::HasAudioOutputDevices() {
   return true;
 }
 
 bool CastAudioManager::HasAudioInputDevices() {
@@ skipping 14 matching lines @@
     const std::string& device_id) {
   LOG(WARNING) << "No support for input audio devices";
   // Need to send a valid AudioParameters object even when it will unused.
   return ::media::AudioParameters(
       ::media::AudioParameters::AUDIO_PCM_LOW_LATENCY,
       ::media::CHANNEL_LAYOUT_STEREO, 48000, 16, 1024);
 }
 
 scoped_ptr<MediaPipelineBackend> CastAudioManager::CreateMediaPipelineBackend(
     const MediaPipelineDeviceParams& params) {
-  return backend_manager_->CreateMediaPipelineBackend(params);
+  DCHECK(media::MediaMessageLoop::GetTaskRunner()->BelongsToCurrentThread());
+
+  return scoped_ptr<MediaPipelineBackend>(
+      MediaPipelineBackendManager::CreateMediaPipelineBackend(params));
 }
 
 ::media::AudioOutputStream* CastAudioManager::MakeLinearOutputStream(
     const ::media::AudioParameters& params) {
   DCHECK_EQ(::media::AudioParameters::AUDIO_PCM_LINEAR, params.format());
   return new CastAudioOutputStream(params, this);
 }
 
 ::media::AudioOutputStream* CastAudioManager::MakeLowLatencyOutputStream(
     const ::media::AudioParameters& params,
@@ skipping 35 matching lines @@
   }
 
   ::media::AudioParameters output_params(
       ::media::AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout,
       sample_rate, bits_per_sample, buffer_size);
   return output_params;
 }
 
 }  // namespace media
 }  // namespace chromecast