Move unrecoverable_error_handler file to util folder.

chrome/browser/sync/unrecoverable_error_handler.h

-// Copyright (c) 2011 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_UNRECOVERABLE_ERROR_HANDLER_H_
-#define CHROME_BROWSER_SYNC_UNRECOVERABLE_ERROR_HANDLER_H_
-#pragma once
-
-#include <string>
-
-#include "base/location.h"
-
-namespace browser_sync {
-
-class UnrecoverableErrorHandler {
- public:
-  // Call this when normal operation detects that the chrome model and the
-  // syncer model are inconsistent, or similar.  The ProfileSyncService will
-  // try to avoid doing any work to avoid crashing or corrupting things
-  // further, and will report an error status if queried.
-  virtual void OnUnrecoverableError(const tracked_objects::Location& from_here,
-                                    const std::string& message) = 0;
- protected:
-  virtual ~UnrecoverableErrorHandler() { }
-};
-
-}
-
-#endif  // CHROME_BROWSER_SYNC_UNRECOVERABLE_ERROR_HANDLER_H_