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

components/sync/engine/fake_model_type_connector.h

Index: components/sync/engine/fake_model_type_connector.h
diff --git a/components/sync/engine/fake_model_type_connector.h b/components/sync/engine/fake_model_type_connector.h
index 978e24aa0eb8638920501391375bfa3704deb327..7c47378dc51cc894d2b022655773652013a9967e 100644
--- a/components/sync/engine/fake_model_type_connector.h
+++ b/components/sync/engine/fake_model_type_connector.h
@@ -17,12 +17,10 @@
   FakeModelTypeConnector();
   ~FakeModelTypeConnector() override;
 
-  void ConnectNonBlockingType(
+  void ConnectType(
       ModelType type,
       std::unique_ptr<ActivationContext> activation_context) override;
-  void DisconnectNonBlockingType(ModelType type) override;
-  void RegisterDirectoryType(ModelType type, ModelSafeGroup group) override;
-  void UnregisterDirectoryType(ModelType type) override;
+  void DisconnectType(ModelType type) override;
 };
 
 }  // namespace syncer