chrome: Cleanup class/struct forward declarations

chrome/browser/ui/app_list/app_list_syncable_service.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_APP_LIST_APP_LIST_SYNCABLE_SERVICE_H_
 #define CHROME_BROWSER_UI_APP_LIST_APP_LIST_SYNCABLE_SERVICE_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 28 matching lines @@
 namespace sync_pb {
 class AppListSpecifics;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 namespace app_list {
 
-class AppListFolderItem;
 class AppListItem;
 class AppListModel;
 
 // Keyed Service that owns, stores, and syncs an AppListModel for a profile.
 class AppListSyncableService : public syncer::SyncableService,
                                public KeyedService,
                                public DriveAppUninstallSyncService {
  public:
   struct SyncItem {
     SyncItem(const std::string& id,
@@ skipping 217 matching lines @@
   std::unique_ptr<DriveAppProvider> drive_app_provider_;
 
   base::WeakPtrFactory<AppListSyncableService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AppListSyncableService);
 };
 
 }  // namespace app_list
 
 #endif  // CHROME_BROWSER_UI_APP_LIST_APP_LIST_SYNCABLE_SERVICE_H_