--- a/testing/talos/talos/startup_test/sessionrestore/addon/bootstrap.js
+++ b/testing/talos/talos/startup_test/sessionrestore/addon/bootstrap.js
@@ -11,17 +11,17 @@ ChromeUtils.import("resource://gre/modul
 ChromeUtils.defineModuleGetter(this, "Services",
   "resource://gre/modules/Services.jsm");
 ChromeUtils.defineModuleGetter(this, "setTimeout",
   "resource://gre/modules/Timer.jsm");
 ChromeUtils.defineModuleGetter(this, "StartupPerformance",
   "resource:///modules/sessionstore/StartupPerformance.jsm");
 
 // Observer Service topics.
-const WINDOW_READY_TOPIC = "browser-delayed-startup-finished";
+const WINDOW_READY_TOPIC = "browser-idle-startup-tasks-finished";
 
 // Process Message Manager topics.
 const MSG_REQUEST = "session-restore-test?duration";
 const MSG_PROVIDE = "session-restore-test:duration";
 
 const sessionRestoreTest = {
   QueryInterface: ChromeUtils.generateQI([Ci.nsIObserver]),
 
@@ -68,17 +68,17 @@ const sessionRestoreTest = {
   onReady(hasRestoredTabs) {
     if (hasRestoredTabs) {
       Services.obs.removeObserver(this, StartupPerformance.RESTORED_TOPIC);
     }
 
     // onReady might fire before the browser window has finished initializing
     // or sometimes soon after. We handle both cases here.
     let win = Services.wm.getMostRecentWindow("navigator:browser");
-    if (!win || !win.gBrowserInit || !win.gBrowserInit.delayedStartupFinished) {
+    if (!win || !win.gBrowserInit || !win.gBrowserInit.idleTasksFinished) {
       // We didn't have a window around yet, so we'll wait until one becomes
       // available before opening the result tab.
       Services.obs.addObserver(this, WINDOW_READY_TOPIC);
     } else {
       // We have a window, so we can open the result tab in it right away.
       this.onWindow(win);
     }