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

chrome/common/extensions/docs/server2/document_parser.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 HTMLParser import HTMLParser
 import logging
 
 
 class ParseResult(object):
   '''The result of |ParseDocument|:
@@ skipping 75 matching lines @@
     return document, 'No opening <h1> was found'
   title_end = min_index('/h1>', '/H1>')
   if title_end == -1:
     return document, 'No closing </h1> was found'
   if title_end < title_start:
     return document, 'The </h1> appeared before the <h1>'
 
   return (document[:title_start] + document[title_end + 4:], None)
 
 
-_HEADER_TAGS = ['h2', 'h3']
+_HEADER_TAGS = ['h2', 'h3', 'h4']
 
 
 class _DocumentParser(HTMLParser):
   '''HTMLParser for ParseDocument.
   '''
 
   def __init__(self, expect_title):
     HTMLParser.__init__(self)
     # Public.
     self.parse_result = None
@@ skipping 25 matching lines @@
                              'will be classified as <h2> for the purpose of '
                              'the structure')
       tag = 'h2'
 
     if tag == 'h1':
       self._title_entry = self._processing_entry
     else:
       belongs_to = self._processing_section.structure
       for header in _HEADER_TAGS[:_HEADER_TAGS.index(tag)]:
         if len(belongs_to) == 0:
-          self._WarnWithPosition('Found <%s> without any preceding <%s>' %
-                                 (tag, header))
+          # TODO(kalman): Re-enable this warning once the reference pages have
+          # their references fixed.
+          #self._WarnWithPosition('Found <%s> without any preceding <%s>' %
+          #                       (tag, header))
           break
         belongs_to = belongs_to[-1].entries
       belongs_to.append(self._processing_entry)
 
   def handle_endtag(self, tag):
     if tag == 'section':
       self._OnSectionBoundary()
       return
 
     if tag != 'h1' and tag not in _HEADER_TAGS:
@@ skipping 45 matching lines @@
 
   def _OnSectionBoundary(self):
     # Only start a new section if the previous section was non-empty.
     if self._processing_section.structure:
       self._sections.append(self._processing_section)
       self._processing_section = DocumentSection()
 
   def _WarnWithPosition(self, message):
     line, col = self.getpos()
     self._warnings.append('%s (line %s, column %s)' % (message, line, col + 1))