Extension docs: Include sidenav in 404 pages

chrome/common/extensions/docs/server2/render_servlet.py

 # Copyright 2013 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.
 
 from fnmatch import fnmatch
 import logging
 import mimetypes
 import os
 import traceback
 
@@ skipping 72 matching lines @@
         content_type = mimetype
       elif path.endswith('.html'):
         content = templates.Render(path)
         content_type = 'text/html'
     except FileNotFoundError as e:
       logging.warning(traceback.format_exc())
       content = None
 
     headers = {'x-frame-options': 'sameorigin'}
     if content is None:
-      return Response.NotFound(templates.Render('404'), headers=headers)
+      doc_class = path.split('/', 1)[0]
+      content = templates.Render(doc_class + '/404')
+      if not content:
+        content = templates.Render('extensions/404')
+      if not content:
+        content = templates.Render('404')

[not at google - send to devlin, 2013/05/24 16:58:29]

third branch here seems unnecessary. we should always have an extensions/404,
you can assert that it's there.

and delete the top-level 404.html. I believe there is also a reference to it in
the integration test.

[方觉(Fang Jue), 2013/05/25 00:08:39]

Yes. It's unnecessary. But before the new 404 templates are merged to stable,
beta, dev, it's not yet always true.

Another choice is to increase the mid version in app.yaml. It seems that
revision pinning also works with branches?

The integration test tries to request 'extensions/notfound.html' and there's no
reference to it. (anyway, presubmit passed)

[not at google - send to devlin, 2013/05/28 14:53:37]

Yes revision pinning works with branches too. Let's do that - remove the third
branch then I can merge this patch through.

+      return Response.NotFound(content, headers=headers)
 
     if not content:
       logging.error('%s had empty content' % path)
 
     headers.update({
       'content-type': content_type,
       'cache-control': 'max-age=300',
     })
     return Response.Ok(content, headers=headers)