Extensions Docs Server: Generalize $ref's to work for any schema node

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

 # Copyright (c) 2012 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.
 
 import logging
 
 from docs_server_utils import FormatKey
 from file_system import FileNotFoundError
 import compiled_file_system as compiled_fs
 from third_party.handlebar import Handlebar
@@ skipping 114 matching lines @@
       'apps_title': 'Apps',
       'extensions_title': 'Extensions',
       'true': True,
       'false': False
     })
     if render_data.errors:
       logging.error('Handlebar error(s) rendering %s:\n%s' %
           (template_name, '  \n'.join(render_data.errors)))
     return render_data.text
 
-  def __getitem__(self, key):
-    return self.get(key)
-
   def get(self, key):
     return self.GetTemplate(self._private_template_path, key)
 
   def GetTemplate(self, base_path, template_name):
     real_path = FormatKey(template_name)
     try:
       return self._cache.GetFromFile(base_path + '/' + real_path)
     except FileNotFoundError as e:
       logging.info(e)
       return None