R=maruel@chromium.org
BUG=None (AFAIK)
TEST=Turn off networking, run gclient runhooks.

Review URL: https://chromiumcodereview.appspot.com/10750007

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@145878 0039d316-1c4b-4281-b951-d872f2087c98