components: Cleanup class/struct fwd declarations

components/offline_pages/offline_page_model_impl.h

 // Copyright 2016 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 COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_IMPL_H_
 #define COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_IMPL_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 20 matching lines @@
 #include "components/offline_pages/offline_page_model.h"
 #include "components/offline_pages/offline_page_model_event_logger.h"
 #include "components/offline_pages/offline_page_storage_manager.h"
 #include "components/offline_pages/offline_page_types.h"
 #include "components/offline_pages/offline_store_types.h"
 
 class GURL;
 namespace base {
 class Clock;
 class SequencedTaskRunner;
-class TimeDelta;
 class TimeTicks;
 }  // namespace base
 
 namespace offline_pages {
 
 struct ClientId;
 struct OfflinePageItem;
 
 class ArchiveManager;
 class ClientPolicyController;
@@ skipping 243 matching lines @@
   base::Clock* testing_clock_;
 
   base::WeakPtrFactory<OfflinePageModelImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OfflinePageModelImpl);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_IMPL_H_