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

client/tests/isolate_smoke_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 os
 import re
 import stat
 import subprocess
 import sys
 import tempfile
 import unittest
 
 ROOT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 sys.path.insert(0, ROOT_DIR)
 
 import isolate
 import isolated_format
+from depot_tools import fix_encoding
 from utils import file_path
 
 import test_utils
 
 
 ALGO = hashlib.sha1
 HASH_NULL = ALGO().hexdigest()
 
 
 # These are per test case, not per mode.
@@ skipping 1026 matching lines @@
     subprocess.check_call(cmd + ['-i', a_isolate], cwd=ROOT_DIR)
 
     # Move the .isolate file aside and rerun the command with the new source but
     # same destination.
     b_isolate = os.path.join(self.tempdir, 'b.isolate')
     os.rename(a_isolate, b_isolate)
     subprocess.check_call(cmd + ['-i', b_isolate], cwd=ROOT_DIR)
 
 
 if __name__ == '__main__':
+  fix_encoding.fix_encoding()
   test_utils.main()