Fix python scripts in src/build/

build/escape_unicode.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.
 
 """Convert any unicode characters found in the input file to C literals."""
 
 import codecs
 import optparse
 import os
 import sys
 
+
 def main(argv):
   parser = optparse.OptionParser()
   usage = 'Usage: %prog -o <output_dir> <input_file>'
   parser.set_usage(usage)
   parser.add_option('-o', dest='output_dir')
 
   options, arglist = parser.parse_args(argv)
 
   if not options.output_dir:
     print "output_dir required"
     return 1
 
   if len(arglist) != 2:
     print "input_file required"
     return 1
 
   in_filename = arglist[1]
 
   if not in_filename.endswith('.utf8'):
     print "input_file should end in .utf8"
     return 1
 
   out_filename = os.path.join(options.output_dir, os.path.basename(
       os.path.splitext(in_filename)[0]))
 
   WriteEscapedFile(in_filename, out_filename)
+  return 0
 
 
 def WriteEscapedFile(in_filename, out_filename):
   input_data = codecs.open(in_filename, 'r', 'utf8').read()
   with codecs.open(out_filename, 'w', 'ascii') as out_file:
     for i, char in enumerate(input_data):
       if ord(char) > 127:
         out_file.write(repr(char.encode('utf8'))[1:-1])
         if input_data[i + 1:i + 2] in '0123456789abcdefABCDEF':
           out_file.write('""')
       else:
         out_file.write(char.encode('ascii'))
 
 
 if __name__ == '__main__':
-  exit(main(sys.argv))
+  sys.exit(main(sys.argv))