[Sync] Make directory types registration explicit in ModelTypeRegistry

components/sync/driver/directory_data_type_controller.cc

Index: components/sync/driver/directory_data_type_controller.cc
diff --git a/components/sync/driver/directory_data_type_controller.cc b/components/sync/driver/directory_data_type_controller.cc
index 86fdd7350e1c831a3c25f2b59c8e989fed95226f..2248b500afbd9dad9bb770f5ec09d474bac9feae 100644
--- a/components/sync/driver/directory_data_type_controller.cc
+++ b/components/sync/driver/directory_data_type_controller.cc
@@ -57,6 +57,11 @@ void DirectoryDataTypeController::GetStatusCounters(
   callback.Run(type(), counters);
 }
 
+void DirectoryDataTypeController::BeforeLoadModels(
+    ModelTypeConfigurer* configurer) {
+  configurer->RegisterDirectoryDataType(type(), model_safe_group_);
+}
+
 void DirectoryDataTypeController::RegisterWithBackend(
     base::Callback<void(bool)> set_downloaded,
     ModelTypeConfigurer* configurer) {}
@@ -74,6 +79,7 @@ void DirectoryDataTypeController::DeactivateDataType(
     ModelTypeConfigurer* configurer) {
   DCHECK(CalledOnValidThread());
   configurer->DeactivateDirectoryDataType(type());
+  configurer->UnregisterDirectoryDataType(type());
 }
 
 // static