Fix python scripts in src/tools/

tools/clang/scripts/update.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.
 
 # Windows can't run .sh files, so this is a small python wrapper around
 # update.sh.
 
 import os
 import subprocess
 import sys
 
-if __name__ == '__main__':
+
+def main():
   if sys.platform in ['win32', 'cygwin']:
-    sys.exit(0)
+    return 0
 
   # This script is called by gclient. gclient opens its hooks subprocesses with
   # (stdout=subprocess.PIPE, stderr=subprocess.STDOUT) and then does custom
   # output processing that breaks printing '\r' characters for single-line
   # updating status messages as printed by curl and wget.
   # Work around this by setting stderr of the update.sh process to stdin (!):
   # gclient doesn't redirect stdin, and while stdin itself is read-only, the
   # subprocess module dup()s it in the child process - and a dup()ed sys.stdin
   # is writable, try
   #   fd2 = os.dup(sys.stdin.fileno()); os.write(fd2, 'hi')
   # TODO: Fix gclient instead, http://crbug.com/95350
-  subprocess.call(
+  return subprocess.call(
       [os.path.join(os.path.dirname(__file__), 'update.sh')] +  sys.argv[1:],
       stderr=sys.stdin)
+
+
+if __name__ == '__main__':
+  sys.exit(main())