[USS] Show USS counters in about:sync page

components/sync/driver/non_blocking_data_type_controller.h

Index: components/sync/driver/non_blocking_data_type_controller.h
diff --git a/components/sync/driver/non_blocking_data_type_controller.h b/components/sync/driver/non_blocking_data_type_controller.h
index d81b8311f1932cb10557e8c851016e3f6f095fb2..3d94e16e1126a17010a629e10be1ffcb22ec6bf6 100644
--- a/components/sync/driver/non_blocking_data_type_controller.h
+++ b/components/sync/driver/non_blocking_data_type_controller.h
@@ -40,6 +40,7 @@ class NonBlockingDataTypeController : public sync_driver::DataTypeController {
   bool ShouldLoadModelBeforeConfigure() const override;
   void LoadModels(const ModelLoadCallback& model_load_callback) override;
   void GetAllNodes(const AllNodesCallback& callback) override;
+  void GetStatusCounters(const StatusCountersCallback& callback) override;
 
   // Registers non-blocking data type with sync backend. In the process the
   // activation context is passed to ModelTypeRegistry, where ModelTypeWorker