Prepare ChromeVox for webstore release.

chrome/browser/resources/chromeos/chromevox/cvox2/background/stubs.js

+// Copyright 2015 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.
+
+/**
+ * @fileoverview Installs stubs for Chrome api's not supported on
+ * specific configurations. Add stubs for new api's that have yet to
+ * land or are not planned for support under specific conditions.
+ */
+
+goog.provide('Stubs');
+
+goog.require('ChromeVoxState');
+
+/** Initializes this module. */
+Stubs.init = function() {
+  if (!cvox.ChromeVox.isChromeOS) {
+    chrome.accessibilityPrivate.onAccessibilityGesture = function() {};
+    chrome.accessibilityPrivate.setFocusRing = function() {};
+    chrome.accessibilityPrivate.setKeyboardListener = function() {};
+    chrome.automation.getDesktop = function() {};
+  }
+};
+
+Stubs.init();