luci-py: Making __file__ usage unicode safe.

client/tools/parallel_execution.py

 # Copyright 2014 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.
 
 """Toolset to run multiple Swarming tasks in parallel."""
 
 import getpass
 import json
 import os
 import optparse
 import subprocess
 import sys
 import tempfile
 import time
 
-BASE_DIR = os.path.dirname(os.path.abspath(__file__))
+BASE_DIR = os.path.dirname(os.path.abspath(
+    __file__.decode(sys.getfilesystemencoding())))
 ROOT_DIR = os.path.dirname(BASE_DIR)
 
 sys.path.insert(0, ROOT_DIR)
 
 import auth
 import isolateserver
 from utils import logging_utils
 from utils import threading_utils
 from utils import tools
 
@@ skipping 157 matching lines @@
     options.swarming = options.swarming.rstrip('/')
     if not options.swarming:
       self.error('--swarming is required.')
     auth.process_auth_options(self, options)
     isolateserver.process_isolate_server_options(self, options, False, True)
     options.dimensions = dict(options.dimensions)
     return options, args
 
   def format_description(self, _):
     return self.description