Add an assert to ensure UTF-8 locale when handling file paths.

client/tests/isolate_test.py

 #!/usr/bin/env python
 # Copyright 2012 The Swarming 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 cStringIO
 import hashlib
 import json
 import logging
 import optparse
 import os
 import shutil
 import subprocess
 import sys
 import tempfile
 
 ROOT_DIR = unicode(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 sys.path.insert(0, ROOT_DIR)
 sys.path.insert(0, os.path.join(ROOT_DIR, 'third_party'))
 
 from depot_tools import auto_stub
+from depot_tools import fix_encoding
 import auth
 import isolate
 import isolate_format
 import isolated_format
 import isolateserver
 from utils import file_path
 from utils import logging_utils
 from utils import tools
 import test_utils
 
@@ skipping 1580 matching lines @@
     cmd = ['run', '--isolate', isolate_file]
     self.assertEqual(0, isolate.CMDrun(optparse.OptionParser(), cmd))
 
 
 def clear_env_vars():
   for e in ('ISOLATE_DEBUG', 'ISOLATE_SERVER'):
     os.environ.pop(e, None)
 
 
 if __name__ == '__main__':
+  fix_encoding.fix_encoding()
   clear_env_vars()
   test_utils.main()