luci-py: Making __file__ usage unicode safe.

client/libs/logdog/tests/streamname_test.py

 #!/usr/bin/env python
 # Copyright 2016 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 import os
 import sys
 import unittest
 import StringIO
 
 ROOT_DIR = os.path.dirname(os.path.abspath(os.path.join(
-    __file__, os.pardir, os.pardir, os.pardir)))
+    __file__.decode(sys.getfilesystemencoding()),
+    os.pardir, os.pardir, os.pardir)))
 sys.path.insert(0, ROOT_DIR)
 
 from libs.logdog import streamname
 
 
 class StreamNameTestCase(unittest.TestCase):
 
   def testInvalidStreamNamesRaiseValueError(self):
     for name in (
         '',
@@ skipping 15 matching lines @@
       raised = False
       try:
         streamname.validate_stream_name(name)
       except ValueError:
         raised = True
       self.assertFalse(raised, "Stream name '%s' raised ValueError" % (name,))
 
 
 if __name__ == '__main__':
   unittest.main()