chrome: Cleanup class/struct forward declarations

chrome/browser/extensions/extension_web_ui.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_EXTENSIONS_EXTENSION_WEB_UI_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_WEB_UI_H_
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "chrome/common/extensions/chrome_manifest_url_handlers.h"
 #include "components/favicon_base/favicon_callback.h"
 #include "content/public/browser/web_ui_controller.h"
 
 class Profile;
 
 namespace content {
 class BrowserContext;
-class WebContents;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 // A collection of methods to handle Chrome URL overrides that are managed by
 // extensions (such as overriding the new tab page).
 // TODO(devlin): Rename this class to ExtensionURLOverrides.
 class ExtensionWebUI {
@@ skipping 44 matching lines @@
  private:
   // Unregister the specified override, and if it's the currently active one,
   // ensure that something takes its place.
   static void UnregisterAndReplaceOverride(const std::string& page,
                                            Profile* profile,
                                            base::ListValue* list,
                                            const base::Value* override);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_WEB_UI_H_