[Sync] Refactor sync configuration logic.

chrome/browser/sync/glue/data_type_manager_impl_unittest.cc

Index: chrome/browser/sync/glue/data_type_manager_impl_unittest.cc
diff --git a/chrome/browser/sync/glue/data_type_manager_impl_unittest.cc b/chrome/browser/sync/glue/data_type_manager_impl_unittest.cc
index c344d48190f300a04d94635b5eb011d985be10af..cc0db2b9808bf1209c365787783cd29a68792d9e 100644
--- a/chrome/browser/sync/glue/data_type_manager_impl_unittest.cc
+++ b/chrome/browser/sync/glue/data_type_manager_impl_unittest.cc
@@ -42,11 +42,11 @@ class FakeBackendDataTypeConfigurer : public BackendDataTypeConfigurer {
 
   virtual void ConfigureDataTypes(
       sync_api::ConfigureReason reason,
-      ModelTypeSet types_to_add,
-      ModelTypeSet types_to_remove,
+      const ModelTypeSet& types_to_add,
+      const ModelTypeSet& types_to_remove,
       NigoriState nigori_state,
-      base::Callback<void(ModelTypeSet)> ready_task,
-      base::Callback<void()> retry_callback) OVERRIDE {
+      const base::Callback<void(ModelTypeSet)>& ready_task,
+      const base::Callback<void()>& retry_callback) OVERRIDE {
     last_nigori_state_ = nigori_state;
     last_ready_task_ = ready_task;
   }