Use browser as mojo_media_services for cast_audio_only builds.

Bug: b:117117082
Change-Id: I14fdddd09de741e763cb9ba6cf69abb58bfdf9ef
Reviewed-on: https://chromium-review.googlesource.com/c/1258317Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Commit-Queue: Alex Leung <alexleung@google.com>
Cr-Commit-Position: refs/heads/master@{#596372}

chromecast/media/DEPS

@@ -9,6 +9,7 @@ include_rules = [
   "+media/audio",
   "+media/base",
   "+media/cdm",
+  "+media/filters",
   "+mojo/core/embedder/embedder.h",
   "+mojo/public/cpp/bindings/binding.h",
   "+ui/gfx/geometry",

chromecast/media/service/cast_mojo_media_client.cc

@@ -4,13 +4,19 @@
 
 #include "chromecast/media/service/cast_mojo_media_client.h"
 
+#include "build/build_config.h"
 #include "chromecast/media/cma/backend/cma_backend_factory.h"
 #include "chromecast/media/service/cast_renderer.h"
 #include "chromecast/public/media/media_pipeline_backend.h"
+#include "media/base/audio_decoder.h"
 #include "media/base/cdm_factory.h"
 #include "media/base/media_log.h"
 #include "media/base/overlay_info.h"
 
+#if defined(OS_ANDROID)
+#include "media/filters/android/media_codec_audio_decoder.h"
+#endif  // defined(OS_ANDROID)
+
 namespace chromecast {
 namespace media {
 
@@ -53,5 +59,13 @@ std::unique_ptr<::media::CdmFactory> CastMojoMediaClient::CreateCdmFactory(
   return create_cdm_factory_cb_.Run();
 }
 
+std::unique_ptr<::media::AudioDecoder> CastMojoMediaClient::CreateAudioDecoder(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
+#if defined(OS_ANDROID)
+  return std::make_unique<::media::MediaCodecAudioDecoder>(task_runner);
+#endif  // defined(OS_ANDROID)
+  return nullptr;
+}
+
 }  // namespace media
 }  // namespace chromecast

chromecast/media/service/cast_mojo_media_client.h

@@ -39,6 +39,8 @@ class CastMojoMediaClient : public ::media::MojoMediaClient {
       const std::string& audio_device_id) override;
   std::unique_ptr<::media::CdmFactory> CreateCdmFactory(
       service_manager::mojom::InterfaceProvider* host_interfaces) override;
+  std::unique_ptr<::media::AudioDecoder> CreateAudioDecoder(
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner) override;
 
  private:
   service_manager::Connector* connector_;

media/media_options.gni

@@ -186,12 +186,20 @@ if (enable_mojo_media) {
     _default_mojo_media_host = "browser"
   } else if (is_android) {
     # Both chrome for Android and cast for Android belongs to this case
-    _default_mojo_media_services = [
-      "cdm",
-      "audio_decoder",
-      "video_decoder",
-    ]
-    _default_mojo_media_host = "gpu"
+    if (is_cast_audio_only) {
+      _default_mojo_media_services = [
+        "cdm",
+        "audio_decoder",
+      ]
+      _default_mojo_media_host = "browser"
+    } else {
+      _default_mojo_media_services = [
+        "cdm",
+        "audio_decoder",
+        "video_decoder",
+      ]
+      _default_mojo_media_host = "gpu"
+    }
   } else if (is_chromeos || is_mac || is_win) {
     _default_mojo_media_services = [ "video_decoder" ]
     _default_mojo_media_host = "gpu"