The Tor Browser / file revision

 var tab;

 function test() {

   // ----------

   // Test setup

   waitForExplicitFinish();

   gPrefService.setBoolPref("browser.zoom.updateBackgroundTabs", true);

   gPrefService.setBoolPref("browser.zoom.siteSpecific", true);

   let uri = "http://example.org/browser/browser/base/content/test/general/dummy_page.html";

   Task.spawn(function () {

     tab = gBrowser.addTab();

     yield FullZoomHelper.load(tab, uri);

     // -------------------------------------------------------------------

     // Test - Trigger a tab switch that should update the zoom level

     yield FullZoomHelper.selectTabAndWaitForLocationChange(tab);

     ok(true, "applyPrefToSetting was called");

   }).then(endTest, FullZoomHelper.failAndContinue(endTest));

 }

 // -------------

 // Test clean-up

 function endTest() {

   Task.spawn(function () {

     yield FullZoomHelper.removeTabAndWaitForLocationChange(tab);

     tab = null;

     if (gPrefService.prefHasUserValue("browser.zoom.updateBackgroundTabs"))

       gPrefService.clearUserPref("browser.zoom.updateBackgroundTabs");

     if (gPrefService.prefHasUserValue("browser.zoom.siteSpecific"))

       gPrefService.clearUserPref("browser.zoom.siteSpecific");

     finish();

   });

 }