[Sync] Remove backend unrecoverable error handler

chrome/browser/sync/glue/sync_backend_host_mock.cc

 // 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.
 
 #include "chrome/browser/sync/glue/sync_backend_host_mock.h"
 
 #include "components/sync_driver/sync_frontend.h"
 
 namespace browser_sync {
 
 const char kTestCacheGuid[] = "test-guid";
 
 SyncBackendHostMock::SyncBackendHostMock() : fail_initial_download_(false) {}
 SyncBackendHostMock::~SyncBackendHostMock() {}
 
 void SyncBackendHostMock::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) {
   frontend->OnBackendInitialized(
       syncer::WeakHandle<syncer::JsBackend>(),
       syncer::WeakHandle<syncer::DataTypeDebugInfoListener>(),
       kTestCacheGuid,
       !fail_initial_download_);
 }
 
@@ skipping 102 matching lines @@
 void SyncBackendHostMock::set_fail_initial_download(bool should_fail) {
   fail_initial_download_ = should_fail;
 }
 
 void SyncBackendHostMock::ClearServerData(
     const syncer::SyncManager::ClearServerDataCallback& callback) {
   NOTIMPLEMENTED();
 }
 
 }  // namespace browser_sync