[Android] Add a configurable environment for devil/.

build/android/devil/utils/mock_calls_test.py

 #!/usr/bin/env python
 # Copyright 2014 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 the contents of mock_calls.py.
 """
 
 import logging
 import os
 import sys
 import unittest
 
+from devil import devil_env
 from devil.android.sdk import version_codes
 from devil.utils import mock_calls
-from pylib import constants
 
-sys.path.append(os.path.join(
-    constants.DIR_SOURCE_ROOT, 'third_party', 'pymock'))
+sys.path.append(devil_env.config.pymock_path)
 import mock # pylint: disable=F0401
 
 
 class _DummyAdb(object):
   def __str__(self):
     return '0123456789abcdef'
 
   def Push(self, host_path, device_path):
     logging.debug('(device %s) pushing %r to %r', self, host_path, device_path)
 
@@ skipping 133 matching lines @@
     self.watchMethodCalls(self.call.adb)
     with self.assertRaises(AssertionError):
       with self.assertCalls():
         self.adb.IsOnline()
 
 
 if __name__ == '__main__':
   logging.getLogger().setLevel(logging.DEBUG)
   unittest.main(verbosity=2)