Shell through to the .bat to make sure the environment is correctly set up. Not sure if there's a better uname to check?
Review URL: https://chromiumcodereview.appspot.com/10024045

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@132252 0039d316-1c4b-4281-b951-d872f2087c98