Cleanup: Remove unneeded forward declarations from chrome/browser/chromeos.

chrome/browser/chromeos/login/language_switch_menu.h

 // Copyright (c) 2011 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_LOGIN_LANGUAGE_SWITCH_MENU_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_LANGUAGE_SWITCH_MENU_H_
 #pragma once
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "testing/gtest/include/gtest/gtest_prod.h"
 #include "views/controls/menu/menu_delegate.h"
 #include "views/controls/menu/view_menu_delegate.h"
 #include "views/view.h"
 
 class WizardControllerTest_SwitchLanguage_Test;
 
 namespace views {
 class MenuItemView;
 class MenuRunner;
 }  // namespace views
 
 namespace chromeos {
 
 class LanguageList;
-class ScreenObserver;
 
 class LanguageSwitchMenu : public views::ViewMenuDelegate,
                            public views::MenuDelegate {
  public:
   LanguageSwitchMenu();
   virtual ~LanguageSwitchMenu();
 
   // Initializes language selection menu contents.
   void InitLanguageMenu();
 
@@ skipping 30 matching lines @@
   // Language locale name storage.
   scoped_ptr<LanguageList> language_list_;
 
   FRIEND_TEST(::WizardControllerTest, SwitchLanguage);
   DISALLOW_COPY_AND_ASSIGN(LanguageSwitchMenu);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_LANGUAGE_SWITCH_MENU_H_