The Tor Browser / file revision

 /* Any copyright is dedicated to the Public Domain.

    http://creativecommons.org/publicdomain/zero/1.0/ */

 function test() {

   waitForExplicitFinish();

   newWindowWithTabView(function (win) {

     registerCleanupFunction(function () win.close());

     let cw = win.TabView.getContentWindow();

     let tab = win.gBrowser.tabs[0];

     let tabItem = tab._tabViewTabItem;

     let isIdle = false;

     // We replace UI.isIdle() here to not rely on setTimeout(). While this

     // function returns false (busy) we expect no tabItem updates to happen.

     let busyCount = 5;

     cw.UI.isIdle = function () {

       return isIdle = (0 > --busyCount);

     };

     cw.TabItems.pausePainting();

     tabItem.addSubscriber("updated", function onUpdated() {

       tabItem.removeSubscriber("updated", onUpdated);

       ok(isIdle, "tabItem is updated only when UI is idle");

       finish();

     });

     cw.TabItems.update(tab);

     cw.TabItems.resumePainting();

   });

 }