[Chromecast] Cleanup the API for creating MediaPipelineBackend.

chromecast/media/audio/cast_audio_output_stream_unittest.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 "base/bind.h"
 #include "base/synchronization/waitable_event.h"
 #include "chromecast/base/metrics/cast_metrics_test_helper.h"
 #include "chromecast/media/audio/cast_audio_manager.h"
 #include "chromecast/media/audio/cast_audio_output_stream.h"
 #include "chromecast/media/base/media_message_loop.h"
@@ skipping 164 matching lines @@
   bool error_;
 };
 
 class FakeAudioManager : public CastAudioManager {
  public:
   FakeAudioManager()
       : CastAudioManager(nullptr), media_pipeline_backend_(nullptr) {}
   ~FakeAudioManager() override {}
 
   // CastAudioManager overrides.
-  scoped_ptr<MediaPipelineBackend> CreateMediaPipelineBackend() override {
+  scoped_ptr<MediaPipelineBackend> CreateMediaPipelineBackend(
+      const MediaPipelineDeviceParams& params) override {
     DCHECK(media::MediaMessageLoop::GetTaskRunner()->BelongsToCurrentThread());
     DCHECK(!media_pipeline_backend_);
 
     scoped_ptr<FakeMediaPipelineBackend> backend(new FakeMediaPipelineBackend);
     // Cache the backend locally to be used by tests.
     media_pipeline_backend_ = backend.get();
     return backend.Pass();
   }
   void ReleaseOutputStream(::media::AudioOutputStream* stream) override {
     DCHECK(media_pipeline_backend_);
@@ skipping 386 matching lines @@
   volume = GetStreamVolume(stream);
   EXPECT_EQ(0.5, volume);
   EXPECT_EQ(0.5f, audio_device->volume_multiplier());
 
   CloseStream(stream);
 }
 
 }  // namespace
 }  // namespace media
 }  // namespace chromecast