Implement layout of NTP apps promo.

chrome/browser/resources/ntp/apps.js

 // Copyright (c) 2010 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.
 
 function getAppsCallback(data) {
   logEvent('received apps');
   var appsSection = $('apps');
   var appsSectionContent = $('apps-maxiview');
   var appsMiniview = appsSection.getElementsByClassName('miniview')[0];
-  appsSectionContent.textContent = '';
+  var appsPromo = $('apps-promo');
+
   appsMiniview.textContent = '';
+  while (appsSectionContent.lastChild != appsPromo) {
+    appsSectionContent.removeChild(appsSectionContent.lastChild);
+  }
 
   clearClosedMenu(apps.menu);
   if (data.apps.length == 0) {
     appsSection.classList.add('disabled');
     layoutSections();
   } else {
     data.apps.forEach(function(app) {
         appsSectionContent.appendChild(apps.createElement(app));
     });
 
@@ skipping 246 matching lines @@
       a.setAttribute('app-id', app['id']);
       a.textContent = app['name'];
       a.href = app['launch_url'];
       a.onclick = handleClick;
       a.style.backgroundImage = url(app['icon_small']);
       a.className = 'item';
       return a;
     },
 
     createWebStoreElement: function() {
-      return createElement({
+      var elm = createElement({
         'id': 'web-store-entry',
         'name': localStrings.getString('web_store_title'),
         'launch_url': localStrings.getString('web_store_url')
       });
+      elm.setAttribute('app-id', 'web-store-entry');
+      return elm;
     }
   };
 })();