temporary fix for repos that directly used DownloadHooks from git_cl.py.

git_cl.py

Index: git_cl.py
diff --git a/git_cl.py b/git_cl.py
index 62b542c6be32ccadf020cebc33b910189b7b40b7..ddca91bae96aeb04c93308b46641d4189fe2bacb 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -1604,6 +1604,9 @@ def DownloadGerritHook(force):
                    'into .git/hooks/commit-msg and '
                    'chmod +x .git/hooks/commit-msg' % src)
 
+# TODO(tandrii): remove this once repos which call this method directly are
+# upgraded.
+DownloadHooks = DownloadGerritHook
 
 @subcommand.usage('[repo root containing codereview.settings]')
 def CMDconfig(parser, args):