Fix python scripts in src/build/

build/escape_unicode.py

Index: build/escape_unicode.py
diff --git a/build/escape_unicode.py b/build/escape_unicode.py
index 5d4410eef7bc92852de4a9893d6d860c5807a51c..859ba5d03d290fa91e5e741ba7d22a61c891b93d 100755
--- a/build/escape_unicode.py
+++ b/build/escape_unicode.py
@@ -1,5 +1,4 @@
-#!/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.
@@ -11,6 +10,7 @@ import optparse
 import os
 import sys
 
+
 def main(argv):
   parser = optparse.OptionParser()
   usage = 'Usage: %prog -o <output_dir> <input_file>'
@@ -37,6 +37,7 @@ def main(argv):
       os.path.splitext(in_filename)[0]))
 
   WriteEscapedFile(in_filename, out_filename)
+  return 0
 
 
 def WriteEscapedFile(in_filename, out_filename):
@@ -52,4 +53,4 @@ def WriteEscapedFile(in_filename, out_filename):
 
 
 if __name__ == '__main__':
-  exit(main(sys.argv))
+  sys.exit(main(sys.argv))