[GRC] Add Tab-scoped Coordination Unit Graph Observer

services/resource_coordinator/resource_coordinator_service.h

Index: services/resource_coordinator/resource_coordinator_service.h
diff --git a/services/resource_coordinator/resource_coordinator_service.h b/services/resource_coordinator/resource_coordinator_service.h
index a56fda5a0799844165c5b26492e692e148c30b9e..c88e81e374dcaeec10600d80c1c65f990635daf5 100644
--- a/services/resource_coordinator/resource_coordinator_service.h
+++ b/services/resource_coordinator/resource_coordinator_service.h
@@ -41,6 +41,9 @@ class ResourceCoordinatorService : public service_manager::Service {
     return ref_factory_.get();
   }
   ukm::MojoUkmRecorder* ukm_recorder() { return ukm_recorder_.get(); }
+  CoordinationUnitManager* coordination_unit_manager() {
+    return &coordination_unit_manager_;
+  }
 
  private:
   service_manager::BinderRegistry registry_;