Fix python scripts in src/chrome/

chrome/browser/chromeos/input_method/litify_proto_file.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.
 
 """Litify a .proto file.
 
 This program add a line
   "option optimize_for = LITE_RUNTIME;"
 to the input .proto file.
 
 Run it like:
   litify_proto_file.py input.proto output.proto
-
 """
 
 import fileinput
 import sys
 
+
 def main(argv):
   if len(argv) != 3:
     print 'Usage: litify_proto_file.py [input] [output]'
-    sys.exit(1)
+    return 1
   output_file = open(sys.argv[2], 'w')
   for line in fileinput.input(sys.argv[1]):
     output_file.write(line)
 
   output_file.write("\noption optimize_for = LITE_RUNTIME;\n")
+  return 0
 
 
 if __name__ == '__main__':
-  main(sys.argv)
+  sys.exit(main(sys.argv))