Added unit tests for switch_access.js.

chrome/browser/resources/chromeos/switch_access/test_support.js

Index: chrome/browser/resources/chromeos/switch_access/test_support.js
diff --git a/chrome/browser/resources/chromeos/switch_access/test_support.js b/chrome/browser/resources/chromeos/switch_access/test_support.js
new file mode 100644
index 0000000000000000000000000000000000000000..ef7f22879a64a7d1151f4085ff5daddc86c349c8
--- /dev/null
+++ b/chrome/browser/resources/chromeos/switch_access/test_support.js
@@ -0,0 +1,13 @@
+// Copyright 2017 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.
+
+/**
+ * Stubs out extension API types and functions, and DOM elements, so
+ * SwitchAccessUnitTest can load.
+ */
+chrome.automation = {};
+
+chrome.automation.getDesktop = function() {};
+
+window = {};