repo: switch default URL to chromium one

Change-Id: I182128a3121873110c8c42003745ac61c11a058d
diff --git a/repo b/repo
index fc6ae42..9b56243 100755
--- a/repo
+++ b/repo
@@ -5,7 +5,7 @@
 import os
 REPO_URL = os.environ.get('REPO_URL', None)
 if not REPO_URL:
-  REPO_URL = 'https://gerrit.googlesource.com/git-repo'
+  REPO_URL = 'https://chromium.googlesource.com/external/repo'
 REPO_REV = 'stable'
 
 # Copyright (C) 2008 Google Inc.