chrome: Cleanup class/struct forward declarations

chrome/browser/chromeos/status/network_menu.h

 // Copyright (c) 2012 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 CHROME_BROWSER_CHROMEOS_STATUS_NETWORK_MENU_H_
 #define CHROME_BROWSER_CHROMEOS_STATUS_NETWORK_MENU_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
 #include "ui/gfx/native_widget_types.h"  // gfx::NativeWindow
 
-class Browser;
-
 namespace ui {
 class MenuModel;
 }
 
-namespace views {
-class MenuItemView;
-class MenuButton;
-class MenuRunner;
-}
-
 namespace chromeos {
 
 class NetworkMenuModel;
 
 // This class builds and manages a ui::MenuModel used to build network
 // menus. It does not represent an actual menu widget. The menu is populated
 // with the list of wifi and mobile networks, and handles connecting to
 // existing networks or spawning UI to configure a new network.
 //
 // This class is now only used to build the dropdown menu in the oobe and
@@ skipping 60 matching lines @@
   // without worrying that they will actually try to happen after the lifetime
   // of this object.
   base::WeakPtrFactory<NetworkMenu> weak_pointer_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NetworkMenu);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_STATUS_NETWORK_MENU_H_