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

components/sync/driver/model_association_manager.h

 // Copyright 2014 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_MODEL_ASSOCIATION_MANAGER_H__
 #define COMPONENTS_SYNC_DRIVER_MODEL_ASSOCIATION_MANAGER_H__
 
 #include <map>
 
 #include "base/macros.h"
@@ skipping 101 matching lines @@
   // Callback passed to each data type controller on starting association. This
   // callback will be invoked when the model association is done.
   void TypeStartCallback(syncer::ModelType type,
                          base::TimeTicks type_start_time,
                          DataTypeController::ConfigureResult start_result,
                          const syncer::SyncMergeResult& local_merge_result,
                          const syncer::SyncMergeResult& syncer_merge_result);
 
   // Callback that will be invoked when the models finish loading. This callback
   // will be passed to |LoadModels| function.
-  void ModelLoadCallback(syncer::ModelType type, syncer::SyncError error);
+  void ModelLoadCallback(syncer::ModelType type,
+                         const syncer::SyncError& error);
 
   // Called when all requested types are associated or association times out.
   // Will clean up any unfinished types, and update |state_| to be |new_state|
   // Finally, it will notify |delegate_| of the configuration result.
   void ModelAssociationDone(State new_state);
 
   // A helper to stop an individual datatype.
   void StopDatatype(const syncer::SyncError& error, DataTypeController* dtc);
 
   // Calls delegate's OnAllDataTypesReadyForConfigure when all datatypes from
@@ skipping 40 matching lines @@
   bool notified_about_ready_for_configure_;
 
   base::WeakPtrFactory<ModelAssociationManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ModelAssociationManager);
 };
 
 }  // namespace sync_driver
 
 #endif  // COMPONENTS_SYNC_DRIVER_MODEL_ASSOCIATION_MANAGER_H__