Pref service: add a factory to create the client lib

services/preferences/public/cpp/pref_store_manager_impl.h

Index: services/preferences/public/cpp/pref_store_manager_impl.h
diff --git a/services/preferences/public/cpp/pref_store_manager_impl.h b/services/preferences/public/cpp/pref_store_manager_impl.h
index 07961579deea37f184d9e46b8125ae83a76c212e..0e9edebfa06af12102f5a8354ff66bd6ed86ec88 100644
--- a/services/preferences/public/cpp/pref_store_manager_impl.h
+++ b/services/preferences/public/cpp/pref_store_manager_impl.h
@@ -97,6 +97,10 @@ class PrefStoreManagerImpl
   // Registered pref stores.
   PrefStorePtrs pref_store_ptrs_;
 
+  // We hold on to the connection request callbacks until all expected
+  // PrefStores have registered.
+  std::vector<ConnectCallback> pending_callbacks_;
+
   mojo::BindingSet<mojom::PrefStoreConnector> connector_bindings_;
   mojo::BindingSet<mojom::PrefStoreRegistry> registry_bindings_;
   std::unique_ptr<PersistentPrefStoreImpl> persistent_pref_store_;
@@ -111,10 +115,6 @@ class PrefStoreManagerImpl
 
   scoped_refptr<base::SequencedWorkerPool> worker_pool_;
 
-  // We hold on to the connection request callbacks until all expected
-  // PrefStores have registered.
-  std::vector<ConnectCallback> pending_callbacks_;
-
   DISALLOW_COPY_AND_ASSIGN(PrefStoreManagerImpl);
 };