chrome: Cleanup class/struct forward declarations

chrome/browser/ui/chrome_pages.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_UI_CHROME_PAGES_H_
 #define CHROME_BROWSER_UI_CHROME_PAGES_H_
 
 #include <stdint.h>
 
 #include <string>
 
 #include "build/build_config.h"
 #include "components/content_settings/core/common/content_settings_types.h"
 #include "url/gurl.h"
 
 #if !defined(OS_ANDROID)
 #include "chrome/browser/signin/signin_promo.h"
 #endif
 
 class Browser;
 class Profile;
 
-namespace content {
-class WebContents;
-}
-
 namespace chrome {
 
 // Sources of requests to show the help tab.
 enum HelpSource {
   // Keyboard accelerators.
   HELP_SOURCE_KEYBOARD,
 
   // Menus (e.g. app menu or Chrome OS system menu).
   HELP_SOURCE_MENU,
 
@@ skipping 60 matching lines @@
 
 // If the user is already signed in, shows the "Signin" portion of Settings,
 // otherwise initiates signin in a new browser tab.
 void ShowBrowserSigninOrSettings(Browser* browser,
                                  signin_metrics::AccessPoint access_point);
 #endif
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_UI_CHROME_PAGES_H_