ensure_goma: use git retry for clone and fetch

scripts/slave/recipe_modules/goma/resources/ensure_goma.py

 #!/usr/bin/env python
 # Copyright 2016 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.
 
 import argparse
 import datetime
 import os
 import shutil
 import subprocess
@@ skipping 30 matching lines @@
   client_dir = args.target_dir
   if not os.path.exists(client_dir):
     os.makedirs(client_dir)
 
   current_repo = subprocess.check_output(
       ['git', 'ls-remote', '--get-url'], cwd=client_dir).strip()
   if current_repo != config['repo']:
     print '[%s]: repo mismatch. initial clone' % (
         datetime.datetime.utcnow() - start)
     shutil.rmtree(client_dir)
-    subprocess.check_call(['git', 'clone', config['repo'], client_dir])
+    subprocess.check_call(['git', 'retry', 'clone', config['repo'], client_dir])
 
   print '[%s]: fetch' % (datetime.datetime.utcnow() - start)
-  subprocess.check_call(['git', 'fetch'], cwd=client_dir)
+  subprocess.check_call(['git', 'retry', 'fetch'], cwd=client_dir)
   rev = config['revision']
   if args.canary:
     rev = 'refs/remotes/origin/HEAD'
   print '[%s]: reset %s' % (datetime.datetime.utcnow() - start, rev)
   subprocess.check_call(
       ['git', 'reset', '--hard', rev], cwd=client_dir)
 
   print '[%s]: download binaries' % (datetime.datetime.utcnow() - start)
   subprocess.check_call([sys.executable,
                          args.download_from_google_storage_path,
                          '--directory',
                          '--recursive',
                          '--bucket', 'chrome-goma',
                          client_dir])
 
   subprocess.check_call(
       [sys.executable, os.path.join(client_dir, 'fix_file_modes.py')])
 
   print '[%s]: done' % (datetime.datetime.utcnow() - start)
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))