Implement GpuArcVideoService for arc video accelerator

components/arc/arc_bridge_service.cc

Index: components/arc/arc_bridge_service.cc
diff --git a/components/arc/arc_bridge_service.cc b/components/arc/arc_bridge_service.cc
index 5e6bcad345bb3f11aa4b5ac60037c2a92cd90eb2..788825db25f601e6753c6e7e3c7f4aa3f6b6350b 100644
--- a/components/arc/arc_bridge_service.cc
+++ b/components/arc/arc_bridge_service.cc
@@ -77,6 +77,17 @@ void ArcBridgeService::RemoveAppObserver(AppObserver* observer) {
   app_observer_list_.RemoveObserver(observer);
 }
 
+void ArcBridgeService::AddVideoServiceObserver(VideoServiceObserver* observer) {
+  DCHECK(CalledOnValidThread());
+  video_service_observer_list_.AddObserver(observer);
+}
+
+void ArcBridgeService::RemoveVideoServiceObserver(
+    VideoServiceObserver* observer) {
+  DCHECK(CalledOnValidThread());
+  video_service_observer_list_.RemoveObserver(observer);
+}
+
 void ArcBridgeService::SetState(State state) {
   DCHECK(CalledOnValidThread());
   // DCHECK on enum classes not supported.