Docserver: Persist stat cache for versioned file systems

chrome/common/extensions/docs/server2/chroot_file_system.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 posixpath
 
 from docs_server_utils import StringIdentity
 from file_system import FileSystem
 from future import Future
 
@@ skipping 26 matching lines @@
                   for path, content in results.iteritems())
     return self._file_system.Read(tuple(prefix(path) for path in paths),
                                   skip_not_found-skip_not_found).Then(next)
 
   def Refresh(self):
     return self._file_system.Refresh()
 
   def Stat(self, path):
     return self._file_system.Stat(posixpath.join(self._root, path))
 
-  def GetIdentity(self):
+  def GetStableIdentity(self):
     return StringIdentity(
         '%s/%s' % (self._file_system.GetIdentity(), self._root))
 
   def __repr__(self):
     return 'ChrootFileSystem(%s, %s)' % (
             self._root, repr(self._file_system))