arc: enable Android tracing in verified-boot mode

components/arc/arc_bridge_service.h

Index: components/arc/arc_bridge_service.h
diff --git a/components/arc/arc_bridge_service.h b/components/arc/arc_bridge_service.h
index d3ee567d7e3a58e3a202ec2b964aa83cb36372f4..07c257317e8067ff63d76910ea1b138c6b1d7771 100644
--- a/components/arc/arc_bridge_service.h
+++ b/components/arc/arc_bridge_service.h
@@ -122,6 +122,7 @@ class ArcBridgeService {
   InstanceHolder<mojom::StorageManagerInstance>* storage_manager() {
     return &storage_manager_;
   }
+  InstanceHolder<mojom::TraceInstance>* trace() { return &trace_; }
   InstanceHolder<mojom::TtsInstance>* tts() { return &tts_; }
   InstanceHolder<mojom::VideoInstance>* video() { return &video_; }
   InstanceHolder<mojom::WallpaperInstance>* wallpaper() { return &wallpaper_; }
@@ -192,6 +193,7 @@ class ArcBridgeService {
   InstanceHolder<mojom::PrintInstance> print_;
   InstanceHolder<mojom::ProcessInstance> process_;
   InstanceHolder<mojom::StorageManagerInstance> storage_manager_;
+  InstanceHolder<mojom::TraceInstance> trace_;
   InstanceHolder<mojom::TtsInstance> tts_;
   InstanceHolder<mojom::VideoInstance> video_;
   InstanceHolder<mojom::WallpaperInstance> wallpaper_;