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

components/sync/driver/shared_change_processor.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_SHARED_CHANGE_PROCESSOR_H_
 #define COMPONENTS_SYNC_DRIVER_SHARED_CHANGE_PROCESSOR_H_
 
+#include <memory>
 #include <string>
 
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
+#include "components/sync/api/data_type_error_handler.h"
 #include "components/sync/api/sync_change_processor.h"
 #include "components/sync/api/sync_data.h"
 #include "components/sync/api/sync_error.h"
 #include "components/sync/api/sync_error_factory.h"
 #include "components/sync/api/sync_merge_result.h"
 #include "components/sync/driver/data_type_controller.h"
 #include "components/sync/engine/model_safe_worker.h"
 
 namespace syncer {
-class DataTypeErrorHandler;
 class SyncableService;
 struct UserShare;
 }  // namespace syncer
 
 namespace sync_driver {
 
 class ChangeProcessor;
 class GenericChangeProcessor;
 class GenericChangeProcessorFactory;
 class SyncClient;
@@ skipping 20 matching lines @@
  public:
   typedef base::Callback<void(
       DataTypeController::ConfigureResult start_result,
       const syncer::SyncMergeResult& local_merge_result,
       const syncer::SyncMergeResult& syncer_merge_result)>
       StartDoneCallback;
 
   // Create an uninitialized SharedChangeProcessor.
   explicit SharedChangeProcessor(syncer::ModelType type);
 
-  void StartAssociation(StartDoneCallback start_done,
-                        SyncClient* const sync_client,
-                        syncer::UserShare* user_share,
-                        syncer::DataTypeErrorHandler* error_handler);
+  void StartAssociation(
+      StartDoneCallback start_done,
+      SyncClient* const sync_client,
+      syncer::UserShare* user_share,
+      std::unique_ptr<syncer::DataTypeErrorHandler> error_handler);
 
   // Connect to the Syncer and prepare to handle changes for |type|. Will
   // create and store a new GenericChangeProcessor and return a weak pointer to
   // the syncer::SyncableService associated with |type|.
   // Note: If this SharedChangeProcessor has been disconnected, or the
   // syncer::SyncableService was not alive, will return a null weak pointer.
   virtual base::WeakPtr<syncer::SyncableService> Connect(
       SyncClient* sync_client,
       GenericChangeProcessorFactory* processor_factory,
       syncer::UserShare* user_share,
-      syncer::DataTypeErrorHandler* error_handler,
+      std::unique_ptr<syncer::DataTypeErrorHandler> error_handler,
       const base::WeakPtr<syncer::SyncMergeResult>& merge_result);
 
   // Disconnects from the generic change processor. May be called from any
   // thread. After this, all attempts to interact with the change processor by
   // |local_service_| are dropped and return errors. The syncer will be safe to
   // shut down from the point of view of this datatype.
   // Note: Once disconnected, you cannot reconnect without creating a new
   // SharedChangeProcessor.
   // Returns: true if we were previously succesfully connected, false if we were
   // already disconnected.
@@ skipping 53 matching lines @@
   // destructed and/or disconnected on this loop, see ~SharedChangeProcessor.
   const scoped_refptr<const base::SingleThreadTaskRunner> frontend_task_runner_;
 
   // The loop that all methods except the constructor, destructor, and
   // Disconnect() should be called on.  Set in Connect().
   scoped_refptr<base::SingleThreadTaskRunner> backend_task_runner_;
 
   // Used only on |backend_loop_|.
   GenericChangeProcessor* generic_change_processor_;
 
-  syncer::DataTypeErrorHandler* error_handler_;
+  std::unique_ptr<syncer::DataTypeErrorHandler> error_handler_;
 
   // The local service for this type. Only set if the DTC for the type uses
   // SharedChangeProcessor::StartAssociation().
   base::WeakPtr<syncer::SyncableService> local_service_;
 
   DISALLOW_COPY_AND_ASSIGN(SharedChangeProcessor);
 };
 
 }  // namespace sync_driver
 
 #endif  // COMPONENTS_SYNC_DRIVER_SHARED_CHANGE_PROCESSOR_H_