Refactor the devserver to make it easier to control caching

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

 #!/usr/bin/env python
 # 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 os
 import sys
 import unittest
 
 from compiled_file_system import CompiledFileSystem
 from example_zipper import ExampleZipper
-from in_memory_object_store import InMemoryObjectStore
 from local_file_system import LocalFileSystem
-from memcache_file_system import MemcacheFileSystem
+from caching_file_system import CachingFileSystem
 
 class ExampleZipperTest(unittest.TestCase):
   def setUp(self):
-    object_store = InMemoryObjectStore('')
-    self._file_system = MemcacheFileSystem(
-        LocalFileSystem(os.path.join(sys.path[0], 'test_data')),
-        object_store)
+    self._file_system = CachingFileSystem(
+        LocalFileSystem(os.path.join(sys.path[0], 'test_data')))
     self._example_zipper = ExampleZipper(
         self._file_system,
-        CompiledFileSystem.Factory(self._file_system, object_store),
+        CompiledFileSystem.Factory(self._file_system),
         'example_zipper')
 
   def testCreateZip(self):
     # Cache manifest.json as unicode and make sure ExampleZipper doesn't error.
     self._file_system.ReadSingle('example_zipper/basic/manifest.json')
     self.assertTrue(len(self._example_zipper.Create('basic')) > 0)
 
 if __name__ == '__main__':
   unittest.main()