Change RepoSync to use -j4 option. Add tests to check for retries.

buildbot/cbuildbot_commands.py

 # Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Module containing the various individual commands a builder can run."""
 
 import os
 import re
 import shutil
 import sys
@@ skipping 35 matching lines @@
 
 
 def _RepoSync(buildroot, retries=_DEFAULT_RETRIES):
   """Uses repo to checkout the source code.
 
   Keyword arguments:
   retries -- Number of retries to try before failing on the sync.
   """
   while retries > 0:
     try:
-      cros_lib.OldRunCommand(['repo', 'sync', '-q'], cwd=buildroot)
+      cros_lib.OldRunCommand(['repo', 'sync', '-q', '--jobs=4'], cwd=buildroot)
       cros_lib.OldRunCommand(
           ['repo',
            'forall',
            '-c',
            'git',
            'config',
            'url.ssh://git@gitrw.chromium.org:9222.insteadof',
            'http://git.chromium.org/git'
           ], cwd=buildroot)
       retries = 0
@@ skipping 377 matching lines @@
 
   archive_url = None
   key_re = re.compile('^%s=(.*)$' % _CROS_ARCHIVE_URL)
   for line in result.output.splitlines():
     line_match = key_re.match(line)
     if line_match:
       archive_url = line_match.group(1)
 
   assert archive_url, 'Archive Build Failed to Provide Archive URL'
   return archive_url