Load CMA backend from shared library

chromecast/media/cma/backend/audio_pipeline_device.cc

Index: chromecast/media/cma/backend/audio_pipeline_device.cc
diff --git a/chromecast/media/cma/backend/audio_pipeline_device.cc b/chromecast/media/cma/backend/audio_pipeline_device.cc
deleted file mode 100644
index 60c6c3092e1671b5a4628bae713e7395c657ff4e..0000000000000000000000000000000000000000
--- a/chromecast/media/cma/backend/audio_pipeline_device.cc
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright 2014 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/cma/backend/audio_pipeline_device.h"
-
-namespace chromecast {
-namespace media {
-
-AudioPipelineDevice::AudioPipelineDevice() {
-}
-
-AudioPipelineDevice::~AudioPipelineDevice() {
-}
-
-}  // namespace media
-}  // namespace chromecast