Fix python scripts in src/chrome/

chrome/test/chromeos/autotest/files/client/deps/pyauto_dep/pyauto_dep.py

-#!/usr/bin/python
-
+#!/usr/bin/env python
 # Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Install the pyauto_dep dependency.
 
 This is done by the Chrome ebuild so this in fact has nothing to do.
 """
 
 import os
 from autotest_lib.client.bin import utils
 
 version = 1
 
 def setup(top_dir):
     return
 
 
-pwd = os.getcwd()
-utils.update_version(pwd + '/src', False, version, setup, None)
+def main():
+  pwd = os.getcwd()
+  utils.update_version(pwd + '/src', False, version, setup, None)
+
+
+if __name__ == '__main__':
+  sys.exit(main())