Add audio_device_id in mojo media ServiceFactory CreateRenderer api.

chromecast/browser/media/cast_renderer.cc

Index: chromecast/browser/media/cast_renderer.cc
diff --git a/chromecast/browser/media/cast_renderer.cc b/chromecast/browser/media/cast_renderer.cc
index 12fc8723d0da6deecee04200506fa8936cd51263..a48026386a53fdbb074aae7645ec7e1b489448fc 100644
--- a/chromecast/browser/media/cast_renderer.cc
+++ b/chromecast/browser/media/cast_renderer.cc
@@ -28,13 +28,25 @@ namespace {
 // Maximum difference between audio frame PTS and video frame PTS
 // for frames read from the DemuxerStream.
 const base::TimeDelta kMaxDeltaFetcher(base::TimeDelta::FromMilliseconds(2000));
+
+int GetStreamType(const std::string& audio_device_id) {

[alokp, 2016/07/12 05:01:30]

This is weird. Where are these stream-type integers defined?

[tianyuwang1, 2016/07/12 15:28:09]

They are not defined in cast_shell, because we didn't want to leak the enums.  
That's why we were using an integer.  They are defined in the caller right now
(Assistant code).   We can switch over to use audio_device_id directly in
MediaBackendPipelineManager.  But I would prefer to do it in a separate cl,
since we need to change multiple places in order to switch from stream_type to
audio_device_id.

I've changed the code so that we can do the mapping between audio_device_id to
stream_type in CastContentBrowserInternal for now.

+  if (audio_device_id ==
+      media::AudioDeviceDescription::kCommunicationsDeviceId) {
+    return 1;
+  } else {
+    return 0;
+  }
+}
+
 }  // namespace
 
 CastRenderer::CastRenderer(
     const CreateMediaPipelineBackendCB& create_backend_cb,
-    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner)
+    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+    const std::string& audio_device_id)
     : create_backend_cb_(create_backend_cb),
       task_runner_(task_runner),
+      audio_device_id_(audio_device_id),
       client_(nullptr),
       cast_cdm_context_(nullptr),
       media_task_runner_factory_(
@@ -65,7 +77,7 @@ void CastRenderer::Initialize(
           : MediaPipelineDeviceParams::kModeSyncPts;
   MediaPipelineDeviceParams params(sync_type, backend_task_runner_.get());
   std::unique_ptr<MediaPipelineBackend> backend =
-      create_backend_cb_.Run(params);
+      create_backend_cb_.Run(params, GetStreamType(audio_device_id_));
 
   // Create pipeline.
   MediaPipelineClient pipeline_client;