[Sync] Remove backend unrecoverable error handler

sync/internal_api/sync_rollback_manager_base.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 SYNC_INTERNAL_API_SYNC_ROLLBACK_MANAGER_BASE_H_
 #define SYNC_INTERNAL_API_SYNC_ROLLBACK_MANAGER_BASE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 82 matching lines @@
       ModelTypeSet models_with_changes) override;
 
  protected:
   base::ObserverList<SyncManager::Observer>* GetObservers();
 
   // Initialize sync backup DB.
   bool InitInternal(
       const base::FilePath& database_location,
       InternalComponentsFactory* internal_components_factory,
       InternalComponentsFactory::StorageOption storage,
-      scoped_ptr<UnrecoverableErrorHandler> unrecoverable_error_handler,
+      const WeakHandle<UnrecoverableErrorHandler>& unrecoverable_error_handler,
       const base::Closure& report_unrecoverable_error_function);
 
   void RegisterDirectoryTypeDebugInfoObserver(
       syncer::TypeDebugInfoObserver* observer) override;
   void UnregisterDirectoryTypeDebugInfoObserver(
       syncer::TypeDebugInfoObserver* observer) override;
   bool HasDirectoryTypeDebugInfoObserver(
       syncer::TypeDebugInfoObserver* observer) override;
   void RequestEmitDebugInfo() override;
 
   bool initialized() const {
     return initialized_;
   }
 
  private:
   void NotifyInitializationSuccess();
   void NotifyInitializationFailure();
 
   bool InitBackupDB(const base::FilePath& sync_folder,
                     InternalComponentsFactory* internal_components_factory,
                     InternalComponentsFactory::StorageOption storage);
 
   bool InitTypeRootNode(ModelType type);
   void InitBookmarkFolder(const std::string& folder);
 
   UserShare share_;
   base::ObserverList<SyncManager::Observer> observers_;
 
-  scoped_ptr<UnrecoverableErrorHandler> unrecoverable_error_handler_;
+  WeakHandle<UnrecoverableErrorHandler> unrecoverable_error_handler_;
   base::Closure report_unrecoverable_error_function_;
 
   scoped_ptr<SyncEncryptionHandler> dummy_handler_;
 
   bool initialized_;
 
   base::WeakPtrFactory<SyncRollbackManagerBase> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncRollbackManagerBase);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_SYNC_ROLLBACK_MANAGER_BASE_H_