Convert Google Now's State Change Gathering Mechanism to use Promises

chrome/browser/resources/google_now/utility.js

 // Copyright (c) 2013 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.
 
 'use strict';
 
 /**
  * @fileoverview Utility objects and functions for Google Now extension.
  * Most important entities here:
  * (1) 'wrapper' is a module used to add error handling and other services to
@@ skipping 419 matching lines @@
 })();
 
 wrapper.instrumentChromeApiFunction('alarms.get', 1);
 wrapper.instrumentChromeApiFunction('alarms.onAlarm.addListener', 0);
 wrapper.instrumentChromeApiFunction('identity.getAuthToken', 1);
 wrapper.instrumentChromeApiFunction('identity.onSignInChanged.addListener', 0);
 wrapper.instrumentChromeApiFunction('identity.removeCachedAuthToken', 1);
 wrapper.instrumentChromeApiFunction('webstorePrivate.getBrowserLogin', 0);
 
 /**
+ * Add task tracking support to Promises.
+ * @override
+ **/

[skare_, 2014/02/11 20:07:44]

tiny tiny nit: */ to close

[robliao, 2014/02/11 21:53:21]

Done.

+Promise.prototype.then = function() {

[skare_, 2014/02/11 20:07:44]

extending prototypes of builtins is warned against, though this is probably in
the less-strict section of the rule vs. e.g. Array or String.

https://google-styleguide.googlecode.com/svn/trunk/javascriptguide.xml#Modify...

[robliao, 2014/02/11 21:53:21]

Unfortunately, this is the only way to get Promises to participate safely in the
tasks system. Since DOM Objects don't support object extension, we can't
subclass.
On 2014/02/11 20:07:44, Travis Skare wrote:

+  var originalThen = Promise.prototype.then;
+  return function(callback) {
+    originalThen.call(this, wrapper.wrapCallback(callback, false));
+  }
+}();
+
+/**
  * Builds the object to manage tasks (mutually exclusive chains of events).
  * @param {function(string, string): boolean} areConflicting Function that
  *     checks if a new task can't be added to a task queue that contains an
  *     existing task.
  * @return {Object} Task manager interface.
  */
 function buildTaskManager(areConflicting) {
   /**
    * Queue of scheduled tasks. The first element, if present, corresponds to the
    * currently running task.
@@ skipping 341 matching lines @@
   // One hour is just an arbitrary amount of time chosen.
   chrome.alarms.create(alarmName, {periodInMinutes: 60});
 
   return {
     addListener: addListener,
     getAuthToken: getAuthToken,
     isSignedIn: isSignedIn,
     removeToken: removeToken
   };
 }