[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 680da27cd25f9761209090867bb07ad37d56b041..54ff1b989b49e54dd8ea2afd88931c6f11468646 100644
--- a/chromecast/public/media/media_pipeline_device_params.h
+++ b/chromecast/public/media/media_pipeline_device_params.h
@@ -5,11 +5,15 @@
 #ifndef CHROMECAST_PUBLIC_MEDIA_MEDIA_PIPELINE_DEVICE_PARAMS_H_
 #define CHROMECAST_PUBLIC_MEDIA_MEDIA_PIPELINE_DEVICE_PARAMS_H_
 
+#include <string>
+
 namespace chromecast {
 class TaskRunner;
 
 namespace media {
 
+enum class AudioContentType;
+
 // Supplies creation parameters to platform-specific pipeline backend.
 struct MediaPipelineDeviceParams {
   enum MediaSyncType {
@@ -37,23 +41,35 @@ 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) {}
+        task_runner(task_runner_in),
+        content_type(content_type_in),
+        device_id(device_id_in) {}
 
   const MediaSyncType sync_type;
   const AudioStreamType audio_type;
@@ -63,6 +79,10 @@ struct MediaPipelineDeviceParams {
   // 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