Fix the windows search path to look in oldest applicable platform dir first

(was looking in newest dir before).

  TEST=none
  R=ojan@chromium.org
  BUG=none

Review URL: http://codereview.chromium.org/353014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@30912 0039d316-1c4b-4281-b951-d872f2087c98