git-gs wasn't finding matches in the chromiumos-overlays
repo as most of the files there are .ebuild.  This fixes that.

BUG=None
TEST='git gs KEYWORDS' now returns matches

Review URL: http://codereview.chromium.org/9861001

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@130397 0039d316-1c4b-4281-b951-d872f2087c98