Docserver: Reorganise the site templates into a single site.html file which

chrome/common/extensions/docs/server2/strings_data_source.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.
 
+import logging
+
 from extensions_paths import JSON_TEMPLATES
 from data_source import DataSource
 
 
 class StringsDataSource(DataSource):
   '''Provides templates with access to a key to string mapping defined in a
   JSON configuration file.
   '''
   def __init__(self, server_instance, _):
     self._cache = server_instance.compiled_fs_factory.ForJson(
         server_instance.host_file_system_provider.GetTrunk())
 
   def _GetStringsData(self):
     return self._cache.GetFromFile('%s/strings.json' % JSON_TEMPLATES)
 
   def Cron(self):
     return self._GetStringsData()
 
   def get(self, key):
-    return self._GetStringsData().Get().get(key)
+    string = self._GetStringsData().Get().get(key)
+    if string is None:
+      logging.warning('String "%s" not found' % key)
+    return string