Privatize StrongBinding lifetime management

services/ui/ws/window_tree_factory.h

 // 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.
 
 #ifndef SERVICES_UI_WS_WINDOW_TREE_FACTORY_H_
 #define SERVICES_UI_WS_WINDOW_TREE_FACTORY_H_
 
 #include "base/macros.h"
-#include "mojo/public/cpp/bindings/strong_binding.h"
 #include "services/ui/public/interfaces/window_tree.mojom.h"
 #include "services/ui/ws/user_id.h"
 
 namespace ui {
 namespace ws {
 
 class WindowServer;
 
 class WindowTreeFactory : public ui::mojom::WindowTreeFactory {
  public:
   WindowTreeFactory(WindowServer* window_server,
                     const UserId& user_id,
-                    const std::string& client_name,
-                    mojom::WindowTreeFactoryRequest request);
- private:
+                    const std::string& client_name);
   ~WindowTreeFactory() override;
 
+ private:
   // ui::mojom::WindowTreeFactory:
   void CreateWindowTree(mojo::InterfaceRequest<mojom::WindowTree> tree_request,
                         mojom::WindowTreeClientPtr client) override;
 
   WindowServer* window_server_;
   const UserId user_id_;
   const std::string client_name_;
-  mojo::StrongBinding<ui::mojom::WindowTreeFactory> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeFactory);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_WINDOW_TREE_FACTORY_H_