Refactor Windows MessageBox fallback code.

chrome/browser/ui/views/simple_message_box_win.h

Index: chrome/browser/ui/views/simple_message_box_win.h
diff --git a/chrome/browser/ui/views/simple_message_box_win.h b/chrome/browser/ui/views/simple_message_box_win.h
deleted file mode 100644
index 9d9b54b29f6859e15d30c9cd60deef4aee0f7a3e..0000000000000000000000000000000000000000
--- a/chrome/browser/ui/views/simple_message_box_win.h
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 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.
-
-#ifndef CHROME_BROWSER_UI_VIEWS_SIMPLE_MESSAGE_BOX_WIN_H_
-#define CHROME_BROWSER_UI_VIEWS_SIMPLE_MESSAGE_BOX_WIN_H_
-
-#include "chrome/browser/ui/simple_message_box.h"
-
-namespace chrome {
-
-MessageBoxResult NativeShowMessageBox(HWND parent,
-                                      const base::string16& title,
-                                      const base::string16& message,
-                                      MessageBoxType type);
-
-}  // namespace chrome
-
-#endif  // CHROME_BROWSER_UI_VIEWS_SIMPLE_MESSAGE_BOX_WIN_H_