The Tor Browser / file revision

 let Cu = Components.utils;

 let Cc = Components.classes;

 let Ci = Components.interfaces;

 Components.utils.import("resource://gre/modules/Services.jsm");

 // Call a function once initialization of SessionStartup is complete

 let afterSessionStartupInitialization =

   function afterSessionStartupInitialization(cb) {

     do_print("Waiting for session startup initialization");

     let observer = function() {

       try {

         do_print("Session startup initialization observed");

         Services.obs.removeObserver(observer, "sessionstore-state-finalized");

         cb();

       } catch (ex) {

         do_throw(ex);

       }

     };

     // We need the Crash Monitor initialized for sessionstartup to run

     // successfully.

     Components.utils.import("resource://gre/modules/CrashMonitor.jsm");

     CrashMonitor.init();

     // Start sessionstartup initialization.

     let startup = Cc["@mozilla.org/browser/sessionstartup;1"].

       getService(Ci.nsIObserver);

     Services.obs.addObserver(startup, "final-ui-startup", false);

     Services.obs.addObserver(startup, "quit-application", false);

     Services.obs.notifyObservers(null, "final-ui-startup", "");

     Services.obs.addObserver(observer, "sessionstore-state-finalized", false);

 };