check-webkit-style script cannot running in Chinese windows.
https://bugs.webkit.org/show_bug.cgi?id=87548

Patch by Xueqing Huang <huangxueqing@baidu.com> on 2013-01-16
Reviewed by Darin Adler.

* Scripts/webkitpy/common/system/platforminfo.py:
(PlatformInfo._win_version_tuple_from_cmd):

git-svn-id: svn://svn.chromium.org/blink/trunk@139924 bbb929c8-8fbe-4397-9dbb-9b2b20218538