[Android] Add a configurable environment for devil/.

build/android/devil/android/battery_utils_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 battery_utils.py
 """
 
 # pylint: disable=protected-access,unused-argument
 
 import logging
-import os
 import sys
 import unittest
 
+from devil import devil_env
 from devil.android import battery_utils
 from devil.android import device_errors
 from devil.android import device_utils
 from devil.android import device_utils_test
 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
 
 _DUMPSYS_OUTPUT = [
     '9,0,i,uid,1000,test_package1',
     '9,0,i,uid,1001,test_package2',
     '9,1000,l,pwi,uid,1',
     '9,1001,l,pwi,uid,2',
     '9,0,l,pws,1728,2000,190,207',
 ]
 
@@ skipping 603 matching lines @@
               ['9,1000,l,pwi,uid,0.0327']),
           (self.call.device.RunShellCommand(
               ['dumpsys', 'battery', 'reset'], check_return=True), [])):
         with self.assertRaises(device_errors.CommandFailedError):
           self.battery._ClearPowerData()
 
 
 if __name__ == '__main__':
   logging.getLogger().setLevel(logging.DEBUG)
   unittest.main(verbosity=2)