Create a new depot_tools_testing_lib to move utility modules there

tests/watchlists_unittest.py

 #!/usr/bin/env python
 # Copyright (c) 2011 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.
 
 """Unit tests for watchlists.py."""
 
 # pylint: disable=E1103,E1120,W0212
 
 import os
 import sys
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
-import super_mox
+from testing_support import super_mox
+
 import watchlists
 
 
 class WatchlistsTest(super_mox.SuperMoxTestBase):
 
   def setUp(self):
     super_mox.SuperMoxTestBase.setUp(self)
     self.mox.StubOutWithMock(watchlists.Watchlists, '_HasWatchlistsFile')
     self.mox.StubOutWithMock(watchlists.Watchlists, '_ContentsOfWatchlistsFile')
     self.mox.StubOutWithMock(watchlists.logging, 'error')
@@ skipping 130 matching lines @@
     wl = watchlists.Watchlists(r'a\path')
     returned_watchers = wl.GetWatchersForPaths(
           [r'chrome\browser\renderer_host\render_widget_host.h'])
     watchlists.os.sep = saved_sep  # revert back os.sep before asserts
     self.assertEqual(returned_watchers, watchers)
 
 
 if __name__ == '__main__':
   import unittest
   unittest.main()