chrome: Cleanup class/struct forward declarations

chrome/browser/status_icons/status_icon_menu_model.h

 // Copyright 2013 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_STATUS_ICONS_STATUS_ICON_MENU_MODEL_H_
 #define CHROME_BROWSER_STATUS_ICONS_STATUS_ICON_MENU_MODEL_H_
 
 #include <map>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "ui/base/models/simple_menu_model.h"
 
 namespace gfx {
 class Image;
 }
 
-class StatusIconMenuModelTest;
-
 // StatusIconMenuModel contains the state of the SimpleMenuModel as well as that
 // of its delegate. This is done so that we can easily identify when the menu
 // model state has changed and can tell the status icon to update the menu. This
 // is necessary some platforms which do not notify us before showing the menu
 // (like Ubuntu Unity).
 class StatusIconMenuModel
     : public ui::SimpleMenuModel,
       public ui::SimpleMenuModel::Delegate,
       public base::SupportsWeakPtr<StatusIconMenuModel> {
  public:
@@ skipping 79 matching lines @@
   ItemStateMap item_states_;
 
   base::ObserverList<Observer> observer_list_;
 
   Delegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(StatusIconMenuModel);
 };
 
 #endif  // CHROME_BROWSER_STATUS_ICONS_STATUS_ICON_MENU_MODEL_H_