Add a Restore() method to ValueStore and make StorageAPI use it

chrome/browser/extensions/api/storage/sync_or_local_value_store_cache.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_API_STORAGE_SYNC_OR_LOCAL_VALUE_STORE_CACHE_H_
 #define CHROME_BROWSER_EXTENSIONS_API_STORAGE_SYNC_OR_LOCAL_VALUE_STORE_CACHE_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/extensions/api/storage/settings_observer.h"
 #include "chrome/browser/extensions/api/storage/settings_storage_quota_enforcer.h"
 #include "chrome/browser/extensions/api/storage/value_store_cache.h"
+#include "sync/api/syncable_service.h"
 
 namespace base {
 class FilePath;
 }
 
+namespace syncer {
+class SyncableService;
+}
+
 namespace extensions {
 
 class SettingsBackend;
 class SettingsStorageFactory;
 
 // ValueStoreCache for the LOCAL and SYNC namespaces. It owns a backend for
 // apps and another for extensions. Each backend takes care of persistence and
 // syncing.
 class SyncOrLocalValueStoreCache : public ValueStoreCache {
  public:
   SyncOrLocalValueStoreCache(
       settings_namespace::Namespace settings_namespace,
       const scoped_refptr<SettingsStorageFactory>& factory,
       const SettingsStorageQuotaEnforcer::Limits& quota,
       const scoped_refptr<SettingsObserverList>& observers,
       const base::FilePath& profile_path);
   virtual ~SyncOrLocalValueStoreCache();
 
-  SettingsBackend* GetAppBackend() const;
-  SettingsBackend* GetExtensionBackend() const;
+  syncer::SyncableService* GetSyncableService(syncer::ModelType type) const;
 
   // ValueStoreCache implementation:
 
   virtual void RunWithValueStoreForExtension(
       const StorageCallback& callback,
       scoped_refptr<const Extension> extension) OVERRIDE;
 
   virtual void DeleteStorageSoon(const std::string& extension_id) OVERRIDE;
 
  private:
   void InitOnFileThread(const scoped_refptr<SettingsStorageFactory>& factory,
                         const SettingsStorageQuotaEnforcer::Limits& quota,
                         const scoped_refptr<SettingsObserverList>& observers,
                         const base::FilePath& profile_path);
 
   settings_namespace::Namespace settings_namespace_;
+  bool initialized_;
   scoped_ptr<SettingsBackend> app_backend_;
   scoped_ptr<SettingsBackend> extension_backend_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncOrLocalValueStoreCache);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_STORAGE_SYNC_OR_LOCAL_VALUE_STORE_CACHE_H_