Support javascript gtests in an extension background page.

chrome/browser/resources/chromeos/chromevox2/cvox2/background/background.chromevoxjstest

+// 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.
+
+// Include test fixture.
+GEN_INCLUDE(['../../../chromevox/testing/chromevox_unittest_base.js']);
+
+/**
+ * Test fixture for cvox2.Background.
+ * @constructor
+ * @extends {ChromeVoxUnitTestBase}
+ */
+function BackgroundTest() {}
+
+BackgroundTest.prototype = {
+  __proto__: ChromeVoxUnitTestBase.prototype,
+
+  /** @override */
+  browsePreload: null,
+
+  /** @override */
+  closureModuleDeps: []
+};
+
+/** Tests ChromeVox classic is in this context. */
+TEST_F('BackgroundTest', 'ClassicNamespaces', function() {
+  assertEquals('object', typeof(cvox));
+  assertEquals('function', typeof(cvox.ChromeVoxBackground));
+});