Add an unittest for background/volume_manager.js

chrome/test/data/file_manager/unit_tests/mocks/mock_file_system.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.
 
 /**
  * Mock class for DOMFileSystem.
  * @param {string} volumeId Volume ID for the file system.
  * @constructor
  */
 function MockFileSystem(volumeId) {

[hirono, 2014/10/24 07:12:22]

Could you reuse TestFileSystem?

https://code.google.com/p/chromium/codesearch#chromium/src/chrome/test/data/f...

It looks the MockFileSystem is almost same.

[yawano, 2014/10/27 00:25:08]

While they are very similar, IMHO, they should be different classes since they
mocks different models.

TestFileSystem mocks a file system which is used around
chrome.fileSystemProvider
(https://developer.chrome.com/apps/fileSystemProvider).
On the other hand, MockFileSystem mocks a file system which is returned from
chrome.fileManagerPrivate.

WDYT?

[hirono, 2014/10/27 02:15:27]

Actually I added TestFileSystem class for testing FileOperationManager.
So I don't mind to use the class for testing Files.app stuff.
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/test/data/f...

-  this.name = '';
-  this.root = new MockFileEntry(volumeId, '/');
+  this.name = volumeId;
+  this.root = new MockDirectoryEntry(this, '/');
 }