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 3c5f391482c31b691da219c83ac3ec743abceacf..1c62fda739aa17827bd308d21037b01f189ce1f7 100644
--- a/components/arc/arc_bridge_service.cc
+++ b/components/arc/arc_bridge_service.cc
@@ -94,6 +94,12 @@ void ArcBridgeService::OnSettingsInstanceReady(
   FOR_EACH_OBSERVER(Observer, observer_list(), OnSettingsInstanceReady());
 }
 
+void ArcBridgeService::OnVideoInstanceReady(VideoInstancePtr video_ptr) {
+  DCHECK(CalledOnValidThread());
+  video_ptr_ = std::move(video_ptr);
+  FOR_EACH_OBSERVER(Observer, observer_list(), OnVideoInstanceReady());
+}
+
 void ArcBridgeService::SetState(State state) {
   DCHECK(CalledOnValidThread());
   // DCHECK on enum classes not supported.