[Chromecast] Add new volume control API to CastMediaShlib

chromecast/public/media/media_pipeline_device_params.h

Index: chromecast/public/media/media_pipeline_device_params.h
diff --git a/chromecast/public/media/media_pipeline_device_params.h b/chromecast/public/media/media_pipeline_device_params.h
index d6ba837c6ccd24b375b42ff1dbed3f23f0716bd7..47375d3cc89f1f773ef89c6e15ac5675f30508b4 100644
--- a/chromecast/public/media/media_pipeline_device_params.h
+++ b/chromecast/public/media/media_pipeline_device_params.h
@@ -12,6 +12,8 @@ class TaskRunner;
 
 namespace media {
 
+enum class AudioContentType;  // See chromecast/public/volume_control.h
+
 // Supplies creation parameters to platform-specific pipeline backend.
 struct MediaPipelineDeviceParams {
   enum MediaSyncType {
@@ -39,44 +41,48 @@ struct MediaPipelineDeviceParams {
     kAudioStreamSoundEffects = 1,
   };
 
-  MediaPipelineDeviceParams(TaskRunner* task_runner_in)
+  MediaPipelineDeviceParams(TaskRunner* task_runner_in,
+                            AudioContentType content_type_in,
+                            const std::string& device_id_in)
       : sync_type(kModeSyncPts),
         audio_type(kAudioStreamNormal),
-        task_runner(task_runner_in) {}
+        task_runner(task_runner_in),
+        content_type(content_type_in),
+        device_id(device_id_in) {}
 
   MediaPipelineDeviceParams(MediaSyncType sync_type_in,
-                            TaskRunner* task_runner_in)
+                            TaskRunner* task_runner_in,
+                            AudioContentType content_type_in,
+                            const std::string& device_id_in)
       : sync_type(sync_type_in),
         audio_type(kAudioStreamNormal),
-        task_runner(task_runner_in) {}
+        task_runner(task_runner_in),
+        content_type(content_type_in),
+        device_id(device_id_in) {}
 
   MediaPipelineDeviceParams(MediaSyncType sync_type_in,
                             AudioStreamType audio_type_in,
-                            TaskRunner* task_runner_in)
+                            TaskRunner* task_runner_in,
+                            AudioContentType content_type_in,
+                            const std::string& device_id_in)
       : sync_type(sync_type_in),
         audio_type(audio_type_in),
-        task_runner(task_runner_in) {}
-
-  // |device_id_in| should be from media/audio/audio_device_description.h or
-  // chromecast/media/base/audio_device_ids.h
-  MediaPipelineDeviceParams(MediaSyncType sync_type_in,
-                            AudioStreamType audio_type_in,
-                            const std::string& device_id_in,
-                            TaskRunner* task_runner_in)
-      : sync_type(sync_type_in),
-        audio_type(audio_type_in),
-        device_id(device_id_in),
-        task_runner(task_runner_in) {}
+        task_runner(task_runner_in),
+        content_type(content_type_in),
+        device_id(device_id_in) {}
 
   const MediaSyncType sync_type;
   const AudioStreamType audio_type;
-  const std::string device_id;
 
   // task_runner allows backend implementations to post tasks to the media
   // thread.  Since all calls from cast_shell into the backend are made on
   // the media thread, this may simplify thread management and safety for
   // some backends.
   TaskRunner* const task_runner;
+
+  // Identifies the content type for volume control.
+  const AudioContentType content_type;
+  const std::string device_id;
 };
 
 }  // namespace media