[Sync] Make directory types registration explicit in ModelTypeRegistry

components/sync/driver/data_type_manager_impl.cc

Index: components/sync/driver/data_type_manager_impl.cc
diff --git a/components/sync/driver/data_type_manager_impl.cc b/components/sync/driver/data_type_manager_impl.cc
index 071d4c42bd447bf55ce6432c90d7285eec89fed0..afb73b00404505dfe3c5ae3fc5b34a954b95ade3 100644
--- a/components/sync/driver/data_type_manager_impl.cc
+++ b/components/sync/driver/data_type_manager_impl.cc
@@ -642,6 +642,12 @@ void DataTypeManagerImpl::StartNextAssociation(AssociationGroup group) {
   model_association_manager_.StartAssociationAsync(types_to_associate);
 }
 
+void DataTypeManagerImpl::OnSingleDataTypeWillStart(ModelType type) {
+  DCHECK(controllers_->find(type) != controllers_->end());
+  DataTypeController* dtc = controllers_->find(type)->second.get();
+  dtc->BeforeLoadModels(configurer_);
+}
+
 void DataTypeManagerImpl::OnSingleDataTypeWillStop(ModelType type,
                                                    const SyncError& error) {
   DataTypeController::TypeMap::const_iterator c_it = controllers_->find(type);