Docserver: make file_system a property of Create

chrome/common/extensions/docs/server2/test_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.
 
 from file_system import FileSystem, FileNotFoundError, StatInfo
 from future import Future
 
 
 def _MoveTo(base, obj):
   '''Returns an object as |obj| moved to |base|. That is,
   _MoveTo('foo/bar', {'a': 'b'}) -> {'foo': {'bar': {'a': 'b'}}}
   '''
   result = {}
   leaf = result
   for k in base.split('/'):
     leaf[k] = {}
     leaf = leaf[k]
   leaf.update(obj)
   return result
 
 
 class TestFileSystem(FileSystem):
   '''A FileSystem backed by an object. Create with an object representing file
   paths such that {'a': {'b': 'hello'}} will resolve Read('a/b') as 'hello',
   Read('a/') as ['b'], and Stat determined by a value incremented via
   IncrementStat.
   '''
 
-  def __init__(self, obj, relative_to=None):
+  def __init__(self, obj, relative_to=None, identity=None):
     assert obj is not None
     self._obj = obj if relative_to is None else _MoveTo(relative_to, obj)
+    self._identity = identity or type(self).__name__
     self._path_stats = {}
     self._global_stat = 0
 
   #
   # FileSystem implementation.
   #
 
   def Read(self, paths, binary=False):
     test_fs = self
     class Delegate(object):
@@ skipping 64 matching lines @@
   # Testing methods.
   #
 
   def IncrementStat(self, path=None):
     if path is not None:
       self._path_stats[path] = self._path_stats.get(path, 0) + 1
     else:
       self._global_stat += 1
 
   def GetIdentity(self):
-    return self.__class__.__name__
+    return self._identity