--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -146,16 +146,22 @@ XPCOMUtils.defineLazyModuleGetter(this, 
 #ifdef MOZ_SAFE_BROWSING
 XPCOMUtils.defineLazyGetter(this, "SafeBrowsing", function() {
   let tmp = {};
   Cu.import("resource://gre/modules/SafeBrowsing.jsm", tmp);
   return tmp.SafeBrowsing;
 });
 #endif
 
+XPCOMUtils.defineLazyGetter(this, "gBrowserNewTabPreloader", function () {
+  let tmp = {};
+  Cu.import("resource://gre/modules/BrowserNewTabPreloader.jsm", tmp);
+  return new tmp.BrowserNewTabPreloader();
+});
+
 let gInitialPages = [
   "about:blank",
   "about:newtab",
   "about:home",
   "about:privatebrowsing",
   "about:sessionrestore"
 ];
 
@@ -1396,16 +1402,22 @@ var gBrowserInit = {
     if (document.mozFullScreen)
       onMozEnteredDomFullscreen();
 
 #ifdef MOZ_SERVICES_SYNC
     // initialize the sync UI
     gSyncUI.init();
 #endif
 
+    // Don't preload new tab pages when the toolbar is hidden
+    // (i.e. when the current window is a popup window).
+    if (window.toolbar.visible) {
+      gBrowserNewTabPreloader.init(window);
+    }
+
     gBrowserThumbnails.init();
     TabView.init();
 
     setUrlAndSearchBarWidthForConditionalForwardButton();
     window.addEventListener("resize", function resizeHandler(event) {
       if (event.target == window)
         setUrlAndSearchBarWidthForConditionalForwardButton();
     });
@@ -1552,16 +1564,20 @@ var gBrowserInit = {
     CombinedStopReload.uninit();
 
     gGestureSupport.init(false);
 
     FullScreen.cleanup();
 
     Services.obs.removeObserver(gPluginHandler.pluginCrashed, "plugin-crashed");
 
+    if (!__lookupGetter__("gBrowserNewTabPreloader")) {
+      gBrowserNewTabPreloader.uninit();
+    }
+
     try {
       gBrowser.removeProgressListener(window.XULBrowserWindow);
       gBrowser.removeTabsProgressListener(window.TabsProgressListener);
     } catch (ex) {
     }
 
     PlacesStarButton.uninit();
 

--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -1378,16 +1378,22 @@
                 Cu.reportError(ex);
               }
             }
 
             // We start our browsers out as inactive, and then maintain
             // activeness in the tab switcher.
             b.docShellIsActive = false;
 
+            // If we just created a new tab that loads the default
+            // newtab url, swap in a preloaded page if possible.
+            if (aURI == BROWSER_NEW_TAB_URL) {
+              gBrowserNewTabPreloader.newTab(t);
+            }
+
             // Check if we're opening a tab related to the current tab and
             // move it to after the current tab.
             // aReferrerURI is null or undefined if the tab is opened from
             // an external application or bookmark, i.e. somewhere other
             // than the current tab.
             if ((aRelatedToCurrent == null ? aReferrerURI : aRelatedToCurrent) &&
                 Services.prefs.getBoolPref("browser.tabs.insertRelatedAfterCurrent")) {
               let newTabPos = (this._lastRelatedTab ||