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

client/tools/run_swarming_tests_on_swarming.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.
 
 """Runs the whole set of swarming client unit tests on swarming itself.
 
 This is done in a few steps:
   - Archive the whole directory as a single .isolated file.
   - Create one test-specific .isolated for each test to run. The file is created
     directly and archived manually with isolateserver.py.
   - Trigger each of these test-specific .isolated file per OS.
   - Get all results out of order.
 """
 
 __version__ = '0.1'
 
 import glob
 import logging
 import os
-import shutil
 import subprocess
 import sys
 import tempfile
 import time
 
 ROOT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 
 # Must be first import.
 import parallel_execution
 
 from third_party import colorama
 from third_party.depot_tools import fix_encoding
+from utils import file_path
 from utils import tools
 
 
 def check_output(cmd):
   return subprocess.check_output([sys.executable] + cmd, cwd=ROOT_DIR)
 
 
 def archive_tree(isolate_server):
   """Archives a whole tree and return the sha1 of the .isolated file.
 
@@ skipping 42 matching lines @@
     ] + isolateds
     if logging.getLogger().isEnabledFor(logging.INFO):
       cmd.append('--verbose')
     items = [i.split() for i in check_output(cmd).splitlines()]
     assert len(items) == len(tests)
     assert all(
         items[i][1].endswith(os.path.basename(tests[i]) + '.isolated')
         for i in xrange(len(tests)))
     return zip(tests, [i[0] for i in items])
   finally:
-    shutil.rmtree(tempdir)
+    file_path.rmtree(tempdir)
 
 
 
 def run_swarming_tests_on_swarming(
     swarming_server, isolate_server, priority, oses, tests, logs,
     no_idempotent):
   """Archives, triggers swarming jobs and gets results."""
   print('Archiving the whole tree.')
   start = time.time()
   tree_isolated = archive_tree(isolate_server)
@@ skipping 100 matching lines @@
       tests,
       options.logs,
       options.no_idempotent)
 
 
 if __name__ == '__main__':
   fix_encoding.fix_encoding()
   tools.disable_buffering()
   colorama.init()
   sys.exit(main())