[Sync] On disabling sync, device info records are removed.

components/sync/device_info/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_DEVICE_INFO_DEVICE_INFO_SERVICE_H_
 #define COMPONENTS_SYNC_DEVICE_INFO_DEVICE_INFO_SERVICE_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 39 matching lines @@
   SyncError MergeSyncData(
       std::unique_ptr<MetadataChangeList> metadata_change_list,
       EntityDataMap entity_data_map) override;
   SyncError ApplySyncChanges(
       std::unique_ptr<MetadataChangeList> metadata_change_list,
       EntityChangeList entity_changes) override;
   void GetData(StorageKeyList storage_keys, DataCallback callback) override;
   void GetAllData(DataCallback callback) override;
   std::string GetClientTag(const EntityData& entity_data) override;
   std::string GetStorageKey(const EntityData& entity_data) override;
+  void DisableSync() override;
 
   // DeviceInfoTracker implementation.
   bool IsSyncing() const override;
   std::unique_ptr<DeviceInfo> GetDeviceInfo(
       const std::string& client_id) const override;
   std::vector<std::unique_ptr<DeviceInfo>> GetAllDeviceInfo() const override;
   void AddObserver(Observer* observer) override;
   void RemoveObserver(Observer* observer) override;
   int CountActiveDevices() const override;
 
@@ skipping 94 matching lines @@
 
   // Used to update our local device info once every pulse interval.
   base::OneShotTimer pulse_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceInfoService);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_DEVICE_INFO_DEVICE_INFO_SERVICE_H_