Update TODO for cleaning up DownloadGerritHooks.

TBR=phajdan.jr@chromium.org,andybons@chromium.org
BUG=579176

Review URL: https://codereview.chromium.org/1762343002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@299110 0039d316-1c4b-4281-b951-d872f2087c98

git_cl.py

@@ -1604,7 +1604,7 @@ def DownloadGerritHook(force):
                    'chmod +x .git/hooks/commit-msg' % src)
 
 # TODO(tandrii): remove this once repos which call this method directly are
-# upgraded.
+# upgraded. See http://crbug.com/579176.
 DownloadHooks = DownloadGerritHook
 
 @subcommand.usage('[repo root containing codereview.settings]')