Implement update notifications for ChromeVox Next.

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

+// Copyright 2016 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 Provides notification support for ChromeVox.
+ */
+
+goog.provide('Notifications');
+
+/**
+ * ChromeVox update notification.
+ * @constructor
+ */
+function UpdateNotification() {
+  this.data = {};
+  this.data.type = 'basic';
+  this.data.iconUrl = '/images/chromevox-16.png';
+  this.data.title = Msgs.getMsg('update_title');
+  this.data.message = Msgs.getMsg('update_message_next');
+}
+
+UpdateNotification.prototype = {
+  /** @return {boolean} */
+  shouldShow: function() {
+    return !localStorage['notifications_update_notification_shown'] &&
+        chrome.runtime.getManifest().version >= '53';
+  },
+
+/** Shows the notification. */
+  show: function() {
+    if (!this.shouldShow())
+      return;
+    chrome.notifications.create('update', this.data);
+    chrome.notifications.onClicked.addListener(
+        this.onClicked.bind(this));
+    chrome.notifications.onClosed.addListener(
+        this.onClosed.bind(this));
+  },
+
+  /**
+   * Handles the chrome.notifications event.
+   * @param {string} notificationId
+   */
+  onClicked: function(notificationId) {
+    var nextUpdatePage = {url: 'cvox2/background/next_update.html'};
+    chrome.tabs.create(nextUpdatePage);
+  },
+
+  /**
+   * Handles the chrome.notifications event.
+   * @param {string} id
+   */
+  onClosed: function(id) {
+    localStorage['notifications_update_notification_shown'] = true;
+  }
+};
+
+/**
+ * Runs notifications that should be shown for startup.
+ */
+Notifications.onStartup = function() {
+  // Only run on background page.
+  if (document.location.href.indexOf('background.html') == -1)
+    return;
+
+  new UpdateNotification().show();
+};