Use 'delegating constructor' in WindowManagerWindowTreeFactory

services/ui/ws/window_manager_window_tree_factory.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/ui/ws/window_manager_window_tree_factory.h"
 
 #include "base/bind.h"
 #include "services/ui/ws/window_manager_window_tree_factory_set.h"
 #include "services/ui/ws/window_server.h"
 #include "services/ui/ws/window_tree.h"
 
 namespace ui {
 namespace ws {
 
 WindowManagerWindowTreeFactory::WindowManagerWindowTreeFactory(
     WindowManagerWindowTreeFactorySet* window_manager_window_tree_factory_set,
     const UserId& user_id,
     mojo::InterfaceRequest<mojom::WindowManagerWindowTreeFactory> request)
-    : window_manager_window_tree_factory_set_(
-          window_manager_window_tree_factory_set),
-      user_id_(user_id),
-      binding_(this),
-      window_tree_(nullptr) {
+    : WindowManagerWindowTreeFactory(window_manager_window_tree_factory_set,
+                                     user_id) {
   if (request.is_pending())
     binding_.Bind(std::move(request));
 }
 
 WindowManagerWindowTreeFactory::~WindowManagerWindowTreeFactory() {}
 
 void WindowManagerWindowTreeFactory::CreateWindowTree(
     mojom::WindowTreeRequest window_tree_request,
     mojom::WindowTreeClientPtr window_tree_client) {
   // CreateWindowTree() can only be called once, so there is no reason to keep
@@ skipping 21 matching lines @@
 void WindowManagerWindowTreeFactory::SetWindowTree(WindowTree* window_tree) {
   DCHECK(!window_tree_);
   window_tree_ = window_tree;
 
   window_manager_window_tree_factory_set_
       ->OnWindowManagerWindowTreeFactoryReady(this);
 }
 
 }  // namespace ws
 }  // namespace ui