make ntp apps promo work correctly

chrome/browser/resources/ntp4/apps_page.js

 // Copyright (c) 2011 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('ntp4', function() {
   'use strict';
 
   var localStrings = new LocalStrings;
 
   var APP_LAUNCH = {
@@ skipping 351 matching lines @@
      */
     createAppsPromoExtras_: function() {
       this.classList.add('webstore');
 
       this.appsPromoExtras_ = $('apps-promo-extras-template').cloneNode(true);
       this.appsPromoExtras_.id = '';
       this.appsPromoHeading_ =
           this.appsPromoExtras_.querySelector('.apps-promo-heading');
       this.appsPromoLink_ =
           this.appsPromoExtras_.querySelector('.apps-promo-link');
+      this.appsPromoLink_.addEventListener('click', this.onClick_.bind(this));
 
       this.appsPromoLogo_ = this.ownerDocument.createElement('img');
       this.appsPromoLogo_.className = 'apps-promo-logo';
       this.appImgContainer_.appendChild(this.appsPromoLogo_);
 
       this.appendChild(this.appsPromoExtras_);
       this.appsPromoExtras_.hidden = false;
     },
 
     /**
@@ skipping 48 matching lines @@
 
     /**
      * Invoked when an app is clicked.
      * @param {Event} e The click event.
      * @private
      */
     onClick_: function(e) {
       var is_promo = this.appsPromoExtras_ &&
           window.getComputedStyle(this.appsPromoExtras_).display != 'none';
       var url = !this.appData_.is_webstore ? '' :
-          is_promo ? appendParam(this.appsPromoLink_.href,
-                                 'utm_source',
-                                 'chrome-ntp-promo') :
+          is_promo ? this.appsPromoLink_.href :
                      appendParam(this.appData_.url,
                                  'utm_source',
                                  'chrome-ntp-icon');
 
       chrome.send('launchApp',
                   [this.appId, APP_LAUNCH.NTP_APPS_MAXIMIZED, url,
                    e.altKey, e.ctrlKey, e.metaKey, e.shiftKey, e.button]);
 
       // Don't allow the click to trigger a link or anything
       e.preventDefault();
@@ skipping 348 matching lines @@
     appNotificationChanged: appNotificationChanged,
     AppsPage: AppsPage,
     launchAppAfterEnable: launchAppAfterEnable,
   };
 });
 
 // TODO(estade): update the content handlers to use ntp namespace instead of
 // making these global.
 var appNotificationChanged = ntp4.appNotificationChanged;
 var launchAppAfterEnable = ntp4.launchAppAfterEnable;