arc: enable Android tracing from chrome://tracing in dev mode

components/arc/arc_bridge_host_impl.cc

Index: components/arc/arc_bridge_host_impl.cc
diff --git a/components/arc/arc_bridge_host_impl.cc b/components/arc/arc_bridge_host_impl.cc
index 437aa1a419e3e08d01e8676dd383e96b69b6e4ac..521f11797e1ba90c231ac3f07b04f2901f1adb7b 100644
--- a/components/arc/arc_bridge_host_impl.cc
+++ b/components/arc/arc_bridge_host_impl.cc
@@ -198,6 +198,11 @@ void ArcBridgeHostImpl::OnStorageManagerInstanceReady(
                   std::move(storage_manager_ptr));
 }
 
+void ArcBridgeHostImpl::OnTracingInstanceReady(
+    mojom::TracingInstancePtr tracing_ptr) {
+  OnInstanceReady(arc_bridge_service_->tracing(), std::move(tracing_ptr));
+}
+
 void ArcBridgeHostImpl::OnTtsInstanceReady(mojom::TtsInstancePtr tts_ptr) {
   OnInstanceReady(arc_bridge_service_->tts(), std::move(tts_ptr));
 }