mash: switch to the new pref service

services/preferences/public/cpp/pref_service_factory.cc

Index: services/preferences/public/cpp/pref_service_factory.cc
diff --git a/services/preferences/public/cpp/pref_service_factory.cc b/services/preferences/public/cpp/pref_service_factory.cc
index 1fae6bc8f59f848b88c6c03c3a3188da8748cf4e..d1a48c3d3794740eebcc6221a1f768feb5f6604d 100644
--- a/services/preferences/public/cpp/pref_service_factory.cc
+++ b/services/preferences/public/cpp/pref_service_factory.cc
@@ -97,10 +97,11 @@ void OnConnectError(
 
 void ConnectToPrefService(service_manager::Connector* connector,
                           scoped_refptr<PrefRegistry> pref_registry,
-                          ConnectCallback callback) {
+                          ConnectCallback callback,
+                          base::StringPiece service_name) {
   auto connector_ptr = make_scoped_refptr(
       new RefCountedInterfacePtr<mojom::PrefStoreConnector>());
-  connector->BindInterface(mojom::kPrefStoreServiceName, &connector_ptr->get());
+  connector->BindInterface(service_name.as_string(), &connector_ptr->get());
   connector_ptr->get().set_connection_error_handler(base::Bind(
       &OnConnectError, connector_ptr, base::Passed(ConnectCallback{callback})));
   auto serialized_pref_registry = SerializePrefRegistry(*pref_registry);