ntp4: don't set shownPageIndex during startup

chrome/browser/resources/ntp4/new_tab.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.
 
 /**
  * @fileoverview New tab page
  * This is the main code for the new tab page used by touch-enabled Chrome
  * browsers.  For now this is still a prototype.
  */
 
@@ skipping 594 matching lines @@
       attribution.hidden = true;
     }
   }
 
   /**
    * Handler for CARD_CHANGED on cardSlider.
    * @param {Event} e The CARD_CHANGED event.
    */
   function cardChangedHandler(e) {
     var page = e.cardSlider.currentCardValue;
-    if (page.classList.contains('apps-page')) {
-      shownPage = templateData['apps_page_id'];
-      shownPageIndex = getAppsPageIndex(page);
-    } else if (page.classList.contains('most-visited-page')) {
-      shownPage = templateData['most_visited_page_id'];
-      shownPageIndex = 0;
-    } else if (page.classList.contains('bookmarks-page')) {
-      shownPage = templateData['bookmarks_page_id'];
-      shownPageIndex = 0;
-    } else {
-      console.error('unknown page selected');
+
+    // Don't change shownPage until startup is done (and page changes actually
+    // reflect user actions).
+    if (!document.documentElement.classList.contains('starting-up')) {
+      if (page.classList.contains('apps-page')) {
+        shownPage = templateData['apps_page_id'];
+        shownPageIndex = getAppsPageIndex(page);
+      } else if (page.classList.contains('most-visited-page')) {
+        shownPage = templateData['most_visited_page_id'];
+        shownPageIndex = 0;
+      } else if (page.classList.contains('bookmarks-page')) {
+        shownPage = templateData['bookmarks_page_id'];
+        shownPageIndex = 0;
+      } else {
+        console.error('unknown page selected');
+      }
+      chrome.send('pageSelected', [shownPage, shownPageIndex]);
     }
-    chrome.send('pageSelected', [shownPage, shownPageIndex]);
 
     // Update the active dot
     var curDot = dotList.getElementsByClassName('selected')[0];
     if (curDot)
       curDot.classList.remove('selected');
     var newPageIndex = e.cardSlider.currentCard;
     dots[newPageIndex].classList.add('selected');
     updatePageSwitchers();
   }
 
@@ skipping 108 matching lines @@
 // TODO(estade): update the content handlers to use ntp namespace instead of
 // making these global.
 var assert = ntp4.assert;
 var getAppsCallback = ntp4.getAppsCallback;
 var appsPrefChangeCallback = ntp4.appsPrefChangeCallback;
 var themeChanged = ntp4.themeChanged;
 var recentlyClosedTabs = ntp4.setRecentlyClosedTabs;
 var setMostVisitedPages = ntp4.setMostVisitedPages;
 
 document.addEventListener('DOMContentLoaded', ntp4.initialize);