ui/base: Move message_box_win.{h,cc} to ui/base/win.

ui/base/ui_base_switches.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.
 
 // Defines all the command-line switches used by ui/base.
 
 #ifndef UI_BASE_UI_BASE_SWITCHES_H_
 #define UI_BASE_UI_BASE_SWITCHES_H_
 #pragma once
 
 #include "base/compiler_specific.h"
 #include "ui/base/ui_export.h"
 
 namespace switches {
 
 UI_EXPORT extern const char kLang[];
 UI_EXPORT extern const char kLocalePak[];
+UI_EXPORT extern const char kNoMessageBox[];
 UI_EXPORT extern const char kTouchOptimizedUI[];
 
 #if defined(OS_MACOSX)
 // TODO(kbr): remove this and the associated old code path:
 // http://crbug.com/105344
 // This isn't really the right place for this switch, but is the most
 // convenient place where it can be shared between
 // src/webkit/plugins/npapi/ and src/content/plugin/ .
 UI_EXPORT extern const char kDisableCompositedCoreAnimationPlugins[];
 #endif
 
 }  // namespace switches
 
 #endif  // UI_BASE_UI_BASE_SWITCHES_H_