Add ability for cbuildbot master to synchronize with cbuildbot slaves.

bin/cbuildbot_unittest.py

 #!/usr/bin/python
 
 # Copyright (c) 2010 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.
 
 """Unittests for cbuildbot.  Needs to be run inside of chroot for mox."""
 
 import __builtin__
 import mox
 import unittest
 
+# Fixes circular dependency error.
+import cbuildbot_comm
 import cbuildbot
 
 class CBuildBotTest(mox.MoxTestBase):
 
   def setUp(self):
     mox.MoxTestBase.setUp(self)
     # Always stub RunCommmand out as we use it in every method.
     self.mox.StubOutWithMock(cbuildbot, 'RunCommand')
     self._test_repos = [['kernel', 'third_party/kernel/files'],
                         ['login_manager', 'platform/login_manager']
@@ skipping 70 matching lines @@
     cbuildbot._UprevFromRevisionList(self._buildroot,
                                      self._test_parsed_string_array)
     self.mox.ReplayAll()
     cbuildbot._UprevPackages(self._buildroot, self._revision_file,
                              self._test_board)
     self.mox.VerifyAll()
 
 
 if __name__ == '__main__':
   unittest.main()