Fix python scripts in src/chrome/

chrome/build_nacl_irt.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.
 
 import optparse
 import os
 import re
 import shutil
 import subprocess
 import sys
@@ skipping 196 matching lines @@
                     help='only emit the transitive inputs to the irt build')
   parser.add_option('--platform', dest='platforms', action='append',
                     default=[],
                     help='add a platform to build for (x86-32|x86-64)')
   parser.add_option('--outdir', dest='outdir',
                     help='directory to out irt to')
   (options, args) = parser.parse_args(argv[1:])
   if args or not options.platforms or (
       not options.inputs and not options.outdir):
     parser.print_help()
-    sys.exit(1)
+    return 1
 
   if options.inputs:
     PrintInputs(options.platforms)
   else:
     BuildIRT(options.platforms, options.outdir)
+  return 0
 
 
 if __name__ == '__main__':
-  Main(sys.argv)
+  sys.exit(Main(sys.argv))