[chromecast] Moves CastAudioOutputStream::Backend to CMA thread.

chromecast/media/cma/BUILD.gn

 # 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.
 
 import("//chromecast/chromecast.gni")
 import("//testing/test.gni")
 
 # Targets may depend on this to bring in every CMA component.
 group("cma") {
   public_deps = [
     "//chromecast/media/cma/backend",
     "//chromecast/media/cma/base",
     "//chromecast/media/cma/pipeline",
   ]
 }
 
-source_set("unittests") {
+source_set("test_support") {
   testonly = true
   sources = [
-    "backend/audio_video_pipeline_device_unittest.cc",
-    "base/balanced_media_task_runner_unittest.cc",
-    "base/buffering_controller_unittest.cc",
-    "base/buffering_frame_provider_unittest.cc",
-    "base/decoder_buffer_adapter_unittest.cc",
-    "base/demuxer_stream_adapter_unittest.cc",
-    "base/demuxer_stream_for_test.cc",
-    "base/demuxer_stream_for_test.h",
-    "base/multi_demuxer_stream_adapter_unittest.cc",
-    "pipeline/audio_video_pipeline_impl_unittest.cc",
     "test/frame_generator_for_test.cc",
     "test/frame_generator_for_test.h",
     "test/frame_segmenter_for_test.cc",
     "test/frame_segmenter_for_test.h",
     "test/mock_frame_consumer.cc",
     "test/mock_frame_consumer.h",
     "test/mock_frame_provider.cc",
     "test/mock_frame_provider.h",
     "test/mock_media_pipeline_backend.cc",
     "test/mock_media_pipeline_backend.h",
+    "test/mock_media_pipeline_backend_factory.cc",
+    "test/mock_media_pipeline_backend_factory.h",
   ]
 
   deps = [
     "//base",
-    "//base:i18n",
-    "//base/test:test_support",
-    "//chromecast/base",
-    "//chromecast/base/metrics:test_support",
-    "//chromecast/common/media:interfaces",
-    "//chromecast/media",
-    "//chromecast/media/audio",
     "//chromecast/media/cma/backend",
     "//chromecast/media/cma/base",
-    "//chromecast/media/cma/pipeline",
-    "//chromecast/public",
     "//media",
     "//media/base:test_support",
     "//testing/gmock",
     "//testing/gtest",
-    "//ui/display",
     "//ui/gfx/geometry",
   ]
+}
+
+source_set("unittests") {
+  testonly = true
+  sources = [
+    "backend/audio_video_pipeline_device_unittest.cc",
+    "base/balanced_media_task_runner_unittest.cc",
+    "base/buffering_controller_unittest.cc",
+    "base/buffering_frame_provider_unittest.cc",
+    "base/decoder_buffer_adapter_unittest.cc",
+    "base/demuxer_stream_adapter_unittest.cc",
+    "base/demuxer_stream_for_test.cc",
+    "base/demuxer_stream_for_test.h",
+    "base/multi_demuxer_stream_adapter_unittest.cc",
+    "pipeline/audio_video_pipeline_impl_unittest.cc",
+  ]
+
+  deps = [
+    ":test_support",
+    "//base",
+    "//base/test:test_support",
+    "//chromecast/base",
+    "//chromecast/media",
+    "//media",
+    "//testing/gmock",
+    "//testing/gtest",
+  ]
 
   data = [
     "//media/test/data/",
   ]
 
   # MultizoneBackendTest verifies rendering delay reported by the backend.
   # Since rendering delay is optional on video platforms, enable this test
   # on audio devices only.
   if (is_cast_audio_only && !is_cast_desktop_build) {
     sources += [ "backend/multizone_backend_unittest.cc" ]
   }
 }