Add an unittest for background/volume_manager.js

chrome/test/data/file_manager/unit_tests/file_operation_manager_unittest.js

 // Copyright 2014 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.
 'use strict';
 
 /**
  * Mock of chrome.runtime.
  * @type {Object}
  * @const
  */
@@ skipping 59 matching lines @@
  */
 var DIRECTORY_SIZE = -1;
 
 /**
  * Creates test file system.
  * @param {string} id File system ID.
  * @param {Object.<string, number>} entries Map of entries' paths and their
  *     size. If the size is equals to DIRECTORY_SIZE, the entry is derectory.
  */
 function createTestFileSystem(id, entries) {
-  var fileSystem = new TestFileSystem(id);
+  var fileSystem = new MockFileSystem(id, 'filesystem:' + id);
   for (var path in entries) {
     if (entries[path] === DIRECTORY_SIZE) {
       fileSystem.entries[path] = new MockDirectoryEntry(fileSystem, path);
     } else {
       fileSystem.entries[path] =
           new MockFileEntry(fileSystem, path, {size: entries[path]});
     }
   }
   return fileSystem;
 }
@@ skipping 333 matching lines @@
     assertTrue(events.some(function(event) {
       return event.type === 'entries-changed' &&
           event.entries[0].fullPath === '/test.zip';
     }));
   }), callback);
 
   fileOperationManager.zipSelection(
       fileSystem.entries['/'],
       [fileSystem.entries['/test.txt']]);
 }