Add *.ebuild to the list of files git-gs will search.

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

git-gs

 #!/bin/sh
-# Copyright (c) 2011 The Chromium Authors. All rights reserved.
+# Copyright (c) 2012 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.
 git grep -n -e "$@" -- "*.h" "*.hpp" "*.cpp" "*.c" "*.cc" "*.cpp" "*.inl"\
    "*.grd" "*.idl" "*.m" "*.mm" "*.py" "*.sh" "*.cfg" "*.tac"\
    "*SConscript" "SConscript*" "*.scons" "*.vcproj" "*.vsprops" "*.make"\
-   "*.gyp" "*.gypi" "*.js" "*.html" "*.css"
+   "*.gyp" "*.gypi" "*.js" "*.html" "*.css" "*.ebuild"