Move ui/base/x/x11_error_tracker to base/x11.

ui/base/x/x11_error_tracker.h

-// Copyright (c) 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 <X11/Xlib.h>
-
-#include "base/basictypes.h"
-#include "ui/base/ui_export.h"
-
-namespace ui {
-
-// X11ErrorTracker catches X11 errors in a non-fatal way. It does so by
-// temporarily changing the X11 error handler. The old error handler is
-// restored when the tracker is destroyed.
-class UI_EXPORT X11ErrorTracker {
- public:
-  X11ErrorTracker();
-  ~X11ErrorTracker();
-
-  // Returns whether an X11 error happened since this function was last called
-  // (or since the creation of the tracker). This is potentially expensive,
-  // since this causes a sync with the X server.
-  bool FoundNewError();
-
- private:
-#if !defined(TOOLKIT_GTK)
-  XErrorHandler old_handler_;
-#endif
-
-  DISALLOW_COPY_AND_ASSIGN(X11ErrorTracker);
-};
-
-}  // namespace ui