[Offline pages] Adding ArchiveManager to abstract offline archives management

components/offline_pages/offline_page_model.h

 // Copyright 2015 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_H_
 #define COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 16 matching lines @@
 #include "components/offline_pages/offline_page_metadata_store.h"
 #include "components/offline_pages/offline_page_storage_manager.h"
 #include "components/offline_pages/offline_page_types.h"
 
 class GURL;
 namespace base {
 class SequencedTaskRunner;
 class Time;
 class TimeDelta;
 class TimeTicks;
-}
+}  // namespace base
 
 namespace offline_pages {
 
 static const char* const kBookmarkNamespace = "bookmark";
 static const int64_t kInvalidOfflineId = 0;
 
 struct ClientId;
 
 class ClientPolicyController;
 struct OfflinePageItem;
@@ skipping 320 matching lines @@
   std::unique_ptr<OfflinePageStorageManager> storage_manager_;
 
   base::WeakPtrFactory<OfflinePageModel> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OfflinePageModel);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_