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

components/sync/device_info/device_info_service.h

Index: components/sync/device_info/device_info_service.h
diff --git a/components/sync/device_info/device_info_service.h b/components/sync/device_info/device_info_service.h
index 700ed1fd26e70853e131192698c65f25016d0a19..c5156d07b0b56cc1db3161d4967054936b5ba1b8 100644
--- a/components/sync/device_info/device_info_service.h
+++ b/components/sync/device_info/device_info_service.h
@@ -57,6 +57,7 @@ class DeviceInfoService : public ModelTypeService, public DeviceInfoTracker {
   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;