Fix python scripts in src/chrome/

chrome/test/pyautolib/chromeos/enable_testing.py

-#!/usr/bin/python
-
+#!/usr/bin/env python
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Enable chrome testing interface on ChromeOS.
 
 Enables chrome automation over a named automation channel on ChromeOS.
 Also, allows passing extra flags to chrome (--extra-chrome-flags).
 The path to named testing interface automation socket is printed out.
 
 Needs to be run with superuser privileges.
 
 Usage:
   sudo python enable_testing.py --extra-chrome-flags="--homepage=about:blank"
 """
 
 import dbus
 import optparse
 import os
+import sys
 
 
 class EnableChromeTestingOnChromeOS(object):
   """Helper to enable chrome testing interface on ChromeOS.
 
   Also, can add additional flags to chrome to be used for testing.
   """
 
   SESSION_MANAGER_INTERFACE = 'org.chromium.SessionManagerInterface'
   SESSION_MANAGER_PATH = '/org/chromium/SessionManager'
   SESSION_MANAGER_SERVICE = 'org.chromium.SessionManager'
 
   def _ParseArgs(self):
     parser = optparse.OptionParser()
     parser.add_option(
         '', '--extra-chrome-flags', action='append', default=[],
         help='Pass extra flags to chrome.')
     self._options, self._args = parser.parse_args()
 
   def Run(self):
     self._ParseArgs()
     assert os.geteuid() == 0, 'Needs superuser privileges.'
     system_bus = dbus.SystemBus()
     manager = dbus.Interface(system_bus.get_object(self.SESSION_MANAGER_SERVICE,
                                                    self.SESSION_MANAGER_PATH),
                              self.SESSION_MANAGER_INTERFACE)
     print manager.EnableChromeTesting(True, self._options.extra_chrome_flags)
+    return 0
 
 
 if __name__ == '__main__':
-  enabler = EnableChromeTestingOnChromeOS()
-  enabler.Run()
+  sys.exit(EnableChromeTestingOnChromeOS().Run())