linux: Move linux_util.h from gfx/ to ui/base/gtk.

ui/base/gtk/menu_label_accelerator_util.h

 // 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.
 
-#ifndef UI_GFX_LINUX_UTIL_H_
-#define UI_GFX_LINUX_UTIL_H_
+#ifndef UI_BASE_GTK_MENU_LABEL_ACCELERATOR_UTIL_H_
+#define UI_BASE_GTK_MENU_LABEL_ACCELERATOR_UTIL_H_
 #pragma once
 
 #include <string>
 
 #include "ui/base/ui_export.h"
 
-namespace gfx {
+namespace ui {
 
 // Change windows accelerator style to GTK style. (GTK uses _ for
 // accelerators.  Windows uses & with && as an escape for &.)
 UI_EXPORT std::string ConvertAcceleratorsFromWindowsStyle(
     const std::string& label);
 
 // Removes the "&" accelerators from a Windows label.
 UI_EXPORT std::string RemoveWindowsStyleAccelerators(const std::string& label);
 
 // Escapes "&" characters by doubling them so that later calling
 // ConvertAcceleratorsFromWindowsStyle() will return the original string (except
 // with "_" characters doubled, to escape them for GTK).
 UI_EXPORT std::string EscapeWindowsStyleAccelerators(const std::string& label);
 
-}  // namespace gfx
+}  // namespace ui
 
-#endif  // UI_GFX_LINUX_UTIL_H_
+#endif  // UI_BASE_GTK_MENU_LABEL_ACCELERATOR_UTIL_H_