Revert of [Sync] Make directory types registration explicit in ModelTypeRegistry

components/sync/engine/fake_model_type_connector.cc

Index: components/sync/engine/fake_model_type_connector.cc
diff --git a/components/sync/engine/fake_model_type_connector.cc b/components/sync/engine/fake_model_type_connector.cc
index 5142c12bee283e70d6356f4f7e61412728185396..59b80266eb7eee26ae710d332143f242ae38c203 100644
--- a/components/sync/engine/fake_model_type_connector.cc
+++ b/components/sync/engine/fake_model_type_connector.cc
@@ -12,15 +12,10 @@
 
 FakeModelTypeConnector::~FakeModelTypeConnector() {}
 
-void FakeModelTypeConnector::ConnectNonBlockingType(
+void FakeModelTypeConnector::ConnectType(
     ModelType type,
     std::unique_ptr<ActivationContext> activation_context) {}
 
-void FakeModelTypeConnector::DisconnectNonBlockingType(ModelType type) {}
-
-void FakeModelTypeConnector::RegisterDirectoryType(ModelType type,
-                                                   ModelSafeGroup group) {}
-
-void FakeModelTypeConnector::UnregisterDirectoryType(ModelType type) {}
+void FakeModelTypeConnector::DisconnectType(ModelType type) {}
 
 }  // namespace syncer