support gitiles smart quoting

tools/md_browser/md_browser.py

 #!/usr/bin/env python
 # Copyright 2015 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.
 
 """Simple Markdown browser for a Git checkout."""
 from __future__ import print_function
 
 import SimpleHTTPServer
 import SocketServer
@@ skipping 131 matching lines @@
       self._DoUnknown()
 
   def _DoMD(self, path):
     extensions = [
         'markdown.extensions.def_list',
         'markdown.extensions.fenced_code',
         'markdown.extensions.tables',
         'markdown.extensions.toc',
         'gitiles_autolink',
         'gitiles_ext_blocks',
+        'gitiles_smart_quotes',
     ]
     extension_configs = {
         'markdown.extensions.toc': {
             'slugify': _gitiles_slugify
         },
     }
 
     contents = self._Read(path[1:])
 
     md = markdown.Markdown(extensions=extensions,
@@ skipping 102 matching lines @@
       contents.text = 'Contents'
       contents.tail = '\n'
       toc_aux = ElementTree.SubElement(toc_node, 'div', {'class': 'toc-aux'})
       toc_aux.text = '\n'
       toc_aux.append(ul_with_the_desired_toc_entries)
       toc_aux.tail = '\n'
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))