mash: switch to the new pref service

services/preferences/public/cpp/pref_service_factory.h

Index: services/preferences/public/cpp/pref_service_factory.h
diff --git a/services/preferences/public/cpp/pref_service_factory.h b/services/preferences/public/cpp/pref_service_factory.h
index 2967af3e685c6f4c4bc6b2375e35ae04a99a517c..04234359d95e8a9ef138ad2453f8c13a59327bcc 100644
--- a/services/preferences/public/cpp/pref_service_factory.h
+++ b/services/preferences/public/cpp/pref_service_factory.h
@@ -14,6 +14,7 @@
 #include <memory>
 
 #include "base/callback.h"
+#include "services/preferences/public/interfaces/preferences.mojom.h"
 
 class PrefRegistry;
 class PrefService;
@@ -34,9 +35,11 @@ using ConnectCallback = base::Callback<void(std::unique_ptr<::PrefService>)>;
 // asynchronous and |callback| will be called when it has been established. All
 // preferences that will be accessed need to be registered in |pref_registry|
 // first.
-void ConnectToPrefService(service_manager::Connector* connector,
-                          scoped_refptr<PrefRegistry> pref_registry,
-                          ConnectCallback callback);
+void ConnectToPrefService(
+    service_manager::Connector* connector,
+    scoped_refptr<PrefRegistry> pref_registry,
+    ConnectCallback callback,
+    base::StringPiece service_name = mojom::kPrefStoreServiceName);
 
 }  // namespace prefs