NTP: Don't show any sections or layout until we receive mv and apps.

chrome/browser/resources/new_new_tab.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.
 
 // To avoid creating tons of unnecessary nodes. We assume we cannot fit more
 // than this many items in the miniview.
 var MAX_MINIVIEW_ITEMS = 15;
 
 // Extra spacing at the top of the layout.
 var LAYOUT_SPACING_TOP = 25;
 
-var loading = true;
-
 function updateSimpleSection(id, section) {
   var elm = $(id);
   var maxiview = getSectionMaxiview(elm);
   if (shownSections & section) {
     $(id).classList.remove('hidden');
     if (maxiview)
       maxiview.classList.remove('hidden');
   } else {
     $(id).classList.add('hidden');
     if (maxiview)
@@ skipping 554 matching lines @@
 // onload.
 
 handleWindowResize();
 
 var localStrings = new LocalStrings();
 
 ///////////////////////////////////////////////////////////////////////////////
 // Things we know are not needed at startup go below here
 
 function afterTransition(f) {
-  if (loading) {
+  if (!isDoneLoading()) {
     // Make sure we do not use a timer during load since it slows down the UI.
     f();
   } else {
     // The duration of all transitions are .15s
     window.setTimeout(f, 150);
   }
 }
 
 // Notification
 
@@ skipping 348 matching lines @@
     shownSections & Section.THUMB);
 
 function mostVisitedPages(data, firstRun, hasBlacklistedUrls) {
   logEvent('received most visited pages');
 
   mostVisited.updateSettingsLink(hasBlacklistedUrls);
   mostVisited.data = data;
   mostVisited.layout();
   layoutSections();
 
-  loading = false;
-
   // Remove class name in a timeout so that changes done in this JS thread are
   // not animated.
   window.setTimeout(function() {
     mostVisited.ensureSmallGridCorrect();
-    document.body.classList.remove('loading');
+    maybeDoneLoading();
   }, 1);
 
   // Only show the first run notification if first run.
   if (firstRun) {
     showFirstRunNotification();
   }
 }
+
+function maybeDoneLoading() {
+  if (mostVisited.data && apps.loaded)
+    document.body.classList.remove('loading');
+}
+
+function isDoneLoading() {
+  return !document.body.classList.contains('loading');
+}