Add png and jpg support to md_browser.

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 120 matching lines @@
     if not full_path.startswith(self.server.top_level):
       self._DoUnknown()
     elif path in ('/base.css', '/doc.css', '/prettify.css'):
       self._DoCSS(path[1:])
     elif not os.path.exists(full_path):
       self._DoNotFound()
     elif path.lower().endswith('.md'):
       self._DoMD(path)
     elif os.path.exists(full_path + '/README.md'):
       self._DoMD(path + '/README.md')
+    elif path.lower().endswith('.png'):
+      self._DoImage(full_path, 'image/png')
+    elif path.lower().endswith('.jpg'):
+      self._DoImage(full_path, 'image/jpeg')
     else:
       self._DoDirListing(full_path)
 
   def _DoMD(self, path):
     extensions = [
         'markdown.extensions.def_list',
         'markdown.extensions.fenced_code',
         'markdown.extensions.tables',
         'markdown.extensions.toc',
         'gitiles_autolink',
@@ skipping 65 matching lines @@
       for d in sorted(dirs):
         if d.startswith('.'):
           continue
         self.wfile.write('<a href="%s/%s">%s/</a><br/>\n' %
                          (self.path.rstrip('/'), d, d))
 
       break
 
     self._WriteTemplate('footer.html')
 
+  def _DoImage(self, full_path, mime_type):
+    self._WriteHeader(mime_type)
+    with open(full_path) as f:
+      self.wfile.write(f.read())
+      f.close()
+
   def _Read(self, relpath, relative_to=None):
     if relative_to is None:
       relative_to = self.server.top_level
     assert not relpath.startswith(os.sep)
     path = os.path.join(relative_to, relpath)
     with codecs.open(path, encoding='utf-8') as fp:
       return fp.read()
 
   def _WriteHeader(self, content_type='text/plain', status_code=200):
     self.send_response(status_code)
@@ skipping 60 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:]))