[Sync] Convert DTCs to be not RefCounted and NonThreadSafe.

components/sync/driver/sync_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_SYNC_SERVICE_H_
 #define COMPONENTS_SYNC_DRIVER_SYNC_SERVICE_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 250 matching lines @@
   virtual syncer::UserShare* GetUserShare() const = 0;
 
   // Returns DeviceInfo provider for the local device.
   virtual LocalDeviceInfoProvider* GetLocalDeviceInfoProvider() const = 0;
 
   // Registers a data type controller with the sync service.  This
   // makes the data type controller available for use, it does not
   // enable or activate the synchronization of the data type (see
   // ActivateDataType).  Takes ownership of the pointer.
   virtual void RegisterDataTypeController(
-      DataTypeController* data_type_controller) = 0;
+      std::unique_ptr<DataTypeController> data_type_controller) = 0;
 
   // Called to re-enable a type disabled by DisableDatatype(..). Note, this does
   // not change the preferred state of a datatype, and is not persisted across
   // restarts.
   virtual void ReenableDatatype(syncer::ModelType type) = 0;
 
   // Return sync token status.
   virtual SyncTokenStatus GetSyncTokenStatus() const = 0;
 
   // Get a description of the sync status for displaying in the user interface.
@@ skipping 56 matching lines @@
  protected:
   SyncService() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SyncService);
 };
 
 }  // namespace sync_driver
 
 #endif  // COMPONENTS_SYNC_DRIVER_SYNC_SERVICE_H_