[Sync] Remove backend unrecoverable error handler

chrome/browser/sync/backend_unrecoverable_error_handler.cc

-// Copyright (c) 2012 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 "base/callback.h"
-
-#include "chrome/browser/sync/backend_unrecoverable_error_handler.h"
-#include "chrome/browser/sync/profile_sync_service.h"
-#include "content/public/browser/browser_thread.h"
-
-using content::BrowserThread;
-
-namespace browser_sync {
-
-BackendUnrecoverableErrorHandler::BackendUnrecoverableErrorHandler(
-    const syncer::WeakHandle<ProfileSyncService>& service) : service_(service) {
-}
-
-BackendUnrecoverableErrorHandler::~BackendUnrecoverableErrorHandler() {
-}
-
-void BackendUnrecoverableErrorHandler::OnUnrecoverableError(
-    const tracked_objects::Location& from_here,
-    const std::string& message) {
-  service_.Call(FROM_HERE,
-                &ProfileSyncService::OnUnrecoverableError,
-                from_here,
-                message);
-}
-
-}  // namespace browser_sync