Show device information in chrome://gcm-internals page.

chrome/browser/resources/gcm_internals.js

 // 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.
 
-cr.define('gcminternals', function() {
+cr.define('gcmInternals', function() {
   'use strict';
 
+  /**
+   * If the info dictionary has property prop, then set the text content of
+   * element to the value of this property.
+   * @param {!Object} info A dictionary of device infos to be displayed.
+   * @param {string} prop Name of the property.
+   * @param {string} element The id of a HTML element.
+   */
+  function setIfExists(info, prop, element) {
+    if (info[prop] !== undefined) {
+      $(element).textContent = info[prop];
+    }
+  }
+
+  /**
+   * Display device informations.
+   * @param {!Object} info A dictionary of device infos to be displayed.
+   */
+  function displayDeviceInfo(info) {
+    setIfExists(info, 'userProfileName', 'profile-name');
+    setIfExists(info, 'profileServiceCreated', 'profile-service-created');
+    setIfExists(info, 'gcmEnabledState', 'gcm-enabled-state');
+    setIfExists(info, 'userSignedIn', 'user-signed-in');
+    setIfExists(info, 'gcmClientCreated', 'gcm-client-created');
+    setIfExists(info, 'gcmClientState', 'gcm-client-state');
+    setIfExists(info, 'gcmClientReady', 'gcm-client-ready');
+    setIfExists(info, 'connectionClientCreated', 'connection-client-created');
+    setIfExists(info, 'connectionState', 'connection-state');
+  }
+
   function initialize() {
+    chrome.send('getGcmInternalsInfo');
+  }
+
+  /**
+   * Callback function accepting a dictionary of info items to be displayed.
+   * @param {!Object} infos A dictionary of info items to be displayed.
+   */
+  function setGcmInternalsInfo(infos) {
+    if (infos['deviceInfo'] != undefined) {

[arv (Not doing code reviews), 2014/03/05 19:44:14]

you probably want !== to distinguish null from undefined.

In practice I think you would be fine with falsy/truthy here unless you need to
do something with the empty string

[arv (Not doing code reviews), 2014/03/05 19:44:14]

Why infos['deviceInfo'] here but infos.deviceInfo below? Be consistent.

[juyik, 2014/03/05 19:58:26]

Done.

[juyik, 2014/03/05 19:58:26]

Done.

+      displayDeviceInfo(infos.deviceInfo);
+    }
   }
 
   // Return an object with all of the exports.
   return {
     initialize: initialize,
+    setGcmInternalsInfo: setGcmInternalsInfo,
   };
 });
 
-document.addEventListener('DOMContentLoaded', gcminternals.initialize);
+document.addEventListener('DOMContentLoaded', gcmInternals.initialize);