The Tor Browser / file revision

 function test() {

   waitForExplicitFinish();

   let tab = gBrowser.addTab("http://example.com");

   tab.linkedBrowser.addEventListener("load", function() {

     tab.linkedBrowser.removeEventListener("load", arguments.callee, true);

     let numLocationChanges = 0;

     let listener = {

       onLocationChange: function() {

         numLocationChanges++;

       }

     };

     gBrowser.addTabsProgressListener(listener);

     // pushState to a new URL (http://example.com/foo").  This should trigger

     // exactly one LocationChange event.

     tab.linkedBrowser.contentWindow.history.pushState(null, null, "foo");

     executeSoon(function() {

       gBrowser.removeTab(tab);

       gBrowser.removeTabsProgressListener(listener);

       is(numLocationChanges, 1,

          "pushState should cause exactly one LocationChange event.");

       finish();

     });

   }, true);

 }