[Sync] Make directory types registration explicit in ModelTypeRegistry

components/sync/engine_impl/model_type_connector_proxy.cc

Index: components/sync/engine_impl/model_type_connector_proxy.cc
diff --git a/components/sync/engine_impl/model_type_connector_proxy.cc b/components/sync/engine_impl/model_type_connector_proxy.cc
index c86311720bd04639cbd555c209e6b071c4e6cb02..86adea02d0ec475229e6fd54620e8f3b4c302601 100644
--- a/components/sync/engine_impl/model_type_connector_proxy.cc
+++ b/components/sync/engine_impl/model_type_connector_proxy.cc
@@ -18,19 +18,32 @@ ModelTypeConnectorProxy::ModelTypeConnectorProxy(
 
 ModelTypeConnectorProxy::~ModelTypeConnectorProxy() {}
 
-void ModelTypeConnectorProxy::ConnectType(
+void ModelTypeConnectorProxy::ConnectNonBlockingType(
     ModelType type,
     std::unique_ptr<ActivationContext> activation_context) {
+  task_runner_->PostTask(FROM_HERE,
+                         base::Bind(&ModelTypeConnector::ConnectNonBlockingType,
+                                    model_type_connector_, type,
+                                    base::Passed(&activation_context)));
+}
+
+void ModelTypeConnectorProxy::DisconnectNonBlockingType(ModelType type) {
   task_runner_->PostTask(
-      FROM_HERE,
-      base::Bind(&ModelTypeConnector::ConnectType, model_type_connector_, type,
-                 base::Passed(&activation_context)));
+      FROM_HERE, base::Bind(&ModelTypeConnector::DisconnectNonBlockingType,
+                            model_type_connector_, type));
 }
 
-void ModelTypeConnectorProxy::DisconnectType(ModelType type) {
+void ModelTypeConnectorProxy::RegisterDirectoryType(ModelType type,
+                                                    ModelSafeGroup group) {
   task_runner_->PostTask(FROM_HERE,
-                         base::Bind(&ModelTypeConnector::DisconnectType,
-                                    model_type_connector_, type));
+                         base::Bind(&ModelTypeConnector::RegisterDirectoryType,
+                                    model_type_connector_, type, group));
+}
+
+void ModelTypeConnectorProxy::UnregisterDirectoryType(ModelType type) {
+  task_runner_->PostTask(
+      FROM_HERE, base::Bind(&ModelTypeConnector::UnregisterDirectoryType,
+                            model_type_connector_, type));
 }
 
 }  // namespace syncer