Fix issue: icons for the apps are flickering while launching.

chrome/browser/resources/extensions/extension_list.js

 // Copyright (c) 2012 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('options', function() {
   'use strict';
 
   /**
    * A lookup helper function to find the first node that has an id (starting
    * at |node| and going up the parent chain).
@@ skipping 14 matching lines @@
    */
   var ExtensionsList = cr.ui.define('div');
 
   /**
    * @type {Object.<string, boolean>} A map from extension id to a boolean
    *     indicating whether the incognito warning is showing. This persists
    *     between calls to decorate.
    */
   var butterBarVisibility = {};
 
+  /**
+   * @type {Object.<string, string>} A map from extension id to last reloaded
+   *     timestamp. The timestamp is recorded when the user click the 'Reload'
+   *     link. It is used to refresh the icon of an unpacked extension.
+   *     This persists between calls to decorate.
+   */
+  var extensionReloadedTimestamp = {};
+
   ExtensionsList.prototype = {
     __proto__: HTMLDivElement.prototype,
 
     /** @override */
     decorate: function() {
       this.textContent = '';
 
       this.showExtensionNodes_();
     },
 
@@ skipping 45 matching lines @@
         node.classList.add('inactive-extension');
 
       if (!extension.userModifiable)
         node.classList.add('may-not-disable');
 
       var idToHighlight = this.getIdQueryParam_();
       if (node.id == idToHighlight)
         node.classList.add('extension-highlight');
 
       var item = node.querySelector('.extension-list-item');
-      var extensionIconUrl = extension.icon;
-      if (extension.allow_reload)
-        extensionIconUrl = extension.icon + '?' + Date.now();
-      item.style.backgroundImage = 'url(' + extensionIconUrl + ')';
+      // Prevent the image cache of extension icon by using the reloaded
+      // timestamp as a query string. The timestamp is recorded when the user
+      // clicks the 'Reload' link. http://crbug.com/159302.
+      if (extensionReloadedTimestamp[extension.id]) {
+        item.style.backgroundImage =
+            'url(' + extension.icon + '?' +
+            extensionReloadedTimestamp[extension.id] + ')';
+      } else {
+        item.style.backgroundImage = 'url(' + extension.icon + ')';
+      }
 
       var title = node.querySelector('.extension-title');
       title.textContent = extension.name;
 
       var version = node.querySelector('.extension-version');
       version.textContent = extension.version;
 
       var locationText = node.querySelector('.location-text');
       locationText.textContent = extension.locationText;
 
@@ skipping 61 matching lines @@
                 extension.homepageProvided ? 'extensionSettingsVisitWebsite' :
                                              'extensionSettingsVisitWebStore');
         siteLink.hidden = false;
       }
 
       if (extension.allow_reload) {
         // The 'Reload' link.
         var reload = node.querySelector('.reload-link');
         reload.addEventListener('click', function(e) {
           chrome.send('extensionSettingsReload', [extension.id]);
+          extensionReloadedTimestamp[extension.id] = Date.now();
         });
         reload.hidden = false;
 
         if (extension.is_platform_app) {
           // The 'Launch' link.
           var launch = node.querySelector('.launch-link');
           launch.addEventListener('click', function(e) {
             chrome.send('extensionSettingsLaunch', [extension.id]);
           });
           launch.hidden = false;
@@ skipping 132 matching lines @@
           topScroll -= pad / 2;
         document.body.scrollTop = topScroll;
       }
     }
   };
 
   return {
     ExtensionsList: ExtensionsList
   };
 });