Docserver: Include <h4> tags in the table of contents, it's needed for the API

chrome/common/extensions/docs/server2/table_of_contents_renderer.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 extensions_paths import PRIVATE_TEMPLATES
 from file_system import FileNotFoundError
 
 
 class TableOfContentsRenderer(object):
   '''Renders a table of contents pulled from a list of DocumentSections
   returned from document_parser.ParseDocument.
 
   This performs key functionality of DocumentRenderer, pulled into its own
   class for testability.
   '''
 
-  def __init__(self, host_file_system, compiled_fs_factory):
+  def __init__(self,
+               host_file_system,
+               compiled_fs_factory,
+               template_renderer):
     self._templates = compiled_fs_factory.ForTemplates(host_file_system)
+    self._template_renderer = template_renderer
 
   def Render(self, sections):
     '''Renders a list of DocumentSections |sections| and returns a tuple
     (text, warnings).
     '''
     path = '%s/table_of_contents.html' % PRIVATE_TEMPLATES
     try:
       table_of_contents_template = self._templates.GetFromFile(path).Get()
     except FileNotFoundError:
       return '', ['%s not found' % path]
 
     def make_toc_items(entries):
       return [{
         'attributes':  [(key, val) for key, val in entry.attributes.iteritems()
                         if key != 'id'],
         'link':        entry.attributes.get('id', ''),
         'subheadings': make_toc_items(entry.entries),
         'title':       entry.name,
       } for entry in entries]
 
     toc_items = []
     for section in sections:
       items_for_section = make_toc_items(section.structure)
       if toc_items and items_for_section:
         items_for_section[0]['separator'] = True
       toc_items.extend(items_for_section)
 
-    table_of_contents = table_of_contents_template.Render({
-      'items': toc_items
-    })
-    return table_of_contents.text, table_of_contents.errors
+    return self._template_renderer.Render(
+        self._templates.GetFromFile(
+            '%s/table_of_contents.html' % PRIVATE_TEMPLATES).Get(),
+        None,  # no request
+        data_sources=('partials'),
+        additional_context={'items': toc_items})