Docserver: Add support for viewing docs with a codereview patch applied

chrome/common/extensions/docs/server2/compiled_file_system.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.
 
 class _CacheEntry(object):
   def __init__(self, cache_data, version):
     self._cache_data = cache_data
     self.version = version
 
 class CompiledFileSystem(object):
@@ skipping 75 matching lines @@
     """
     if not path.endswith('/'):
       path += '/'
     version = self._file_system.Stat(path).version
     cache_entry = self._list_object_store.Get(path).Get()
     if (cache_entry is not None) and (version == cache_entry.version):
         return cache_entry._cache_data
     cache_data = self._populate_function(path, self._RecursiveList(path))
     self._list_object_store.Set(path, _CacheEntry(cache_data, version))
     return cache_data
+
+  def StatFile(self, path):
+    cache_entry = self._file_object_store.Get(path).Get()
+    if cache_entry is not None:
+      return cache_entry.version
+    return self._file_system.Stat(path).version
+
+  def StatFileListing(self, path):
+    if not path.endswith('/'):
+      path += '/'
+    cache_entry = self._list_object_store.Get(path).Get()
+    if cache_entry is not None:
+      return cache_entry.version
+    return self._file_system.Stat(path).version