[Sync] Adding storage key concept for ModelTypeServices.

components/sync_driver/device_info_service.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_SYNC_DRIVER_DEVICE_INFO_SERVICE_H_
 #define COMPONENTS_SYNC_DRIVER_DEVICE_INFO_SERVICE_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 44 matching lines @@
 
   // ModelTypeService implementation.
   std::unique_ptr<syncer_v2::MetadataChangeList> CreateMetadataChangeList()
       override;
   syncer::SyncError MergeSyncData(
       std::unique_ptr<syncer_v2::MetadataChangeList> metadata_change_list,
       syncer_v2::EntityDataMap entity_data_map) override;
   syncer::SyncError ApplySyncChanges(
       std::unique_ptr<syncer_v2::MetadataChangeList> metadata_change_list,
       syncer_v2::EntityChangeList entity_changes) override;
-  void GetData(ClientTagList client_tags, DataCallback callback) override;
+  void GetData(StorageKeyList storage_keys, DataCallback callback) override;
   void GetAllData(DataCallback callback) override;
   std::string GetClientTag(const syncer_v2::EntityData& entity_data) override;
+  std::string GetStorageKey(const syncer_v2::EntityData& entity_data) override;
   void OnChangeProcessorSet() override;
 
   // DeviceInfoTracker implementation.
   bool IsSyncing() const override;
   std::unique_ptr<sync_driver::DeviceInfo> GetDeviceInfo(
       const std::string& client_id) const override;
   ScopedVector<sync_driver::DeviceInfo> GetAllDeviceInfo() const override;
   void AddObserver(Observer* observer) override;
   void RemoveObserver(Observer* observer) override;
   int CountActiveDevices() const override;
@@ skipping 103 matching lines @@
 
   // Should always be last member.
   base::WeakPtrFactory<DeviceInfoService> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceInfoService);
 };
 
 }  // namespace sync_driver_v2
 
 #endif  // COMPONENTS_SYNC_DRIVER_DEVICE_INFO_SERVICE_H_