[Sync] Remove backend unrecoverable error handler

chrome/browser/sync/glue/sync_backend_host_mock.h

 // Copyright 2013 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 CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_MOCK_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_MOCK_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 15 matching lines @@
   ~SyncBackendHostMock() override;
 
   void Initialize(
       sync_driver::SyncFrontend* frontend,
       scoped_ptr<base::Thread> sync_thread,
       const syncer::WeakHandle<syncer::JsEventHandler>& event_handler,
       const GURL& service_url,
       const syncer::SyncCredentials& credentials,
       bool delete_sync_data_folder,
       scoped_ptr<syncer::SyncManagerFactory> sync_manager_factory,
-      scoped_ptr<syncer::UnrecoverableErrorHandler> unrecoverable_error_handler,
+      const syncer::WeakHandle<syncer::UnrecoverableErrorHandler>&
+          unrecoverable_error_handler,
       const base::Closure& report_unrecoverable_error_function,
       syncer::NetworkResources* network_resources,
       scoped_ptr<syncer::SyncEncryptionHandler::NigoriState> saved_nigori_state)
       override;
 
   void UpdateCredentials(const syncer::SyncCredentials& credentials) override;
 
   void StartSyncingWithServer() override;
 
   void SetEncryptionPassphrase(const std::string& passphrase,
@@ skipping 66 matching lines @@
 
   void set_fail_initial_download(bool should_fail);
 
  private:
   bool fail_initial_download_;
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_MOCK_H_