chrome: Cleanup class/struct forward declarations

chrome/browser/ui/webui/signin/user_manager_screen_handler.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_UI_WEBUI_SIGNIN_USER_MANAGER_SCREEN_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SIGNIN_USER_MANAGER_SCREEN_HANDLER_H_
 
 #include <map>
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_metrics.h"
 #include "chrome/browser/profiles/profile_statistics.h"
 #include "components/proximity_auth/screenlock_bridge.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/web_ui_message_handler.h"
 #include "google_apis/gaia/gaia_oauth_client.h"
 
 class AccountId;
 class Browser;
-class GaiaAuthFetcher;
 
 namespace base {
 class DictionaryValue;
 class FilePath;
 class ListValue;
 }
 
 class UserManagerScreenHandler
     : public content::WebUIMessageHandler,
       public proximity_auth::ScreenlockBridge::LockHandler,
@@ skipping 98 matching lines @@
 
   // The CancelableTaskTracker is currently used by GetProfileStatistics
   base::CancelableTaskTracker tracker_;
 
   base::WeakPtrFactory<UserManagerScreenHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UserManagerScreenHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SIGNIN_USER_MANAGER_SCREEN_HANDLER_H_