Bugzilla Bug 343709 No way to skin Undo Close Tab menuitem without using English (r=gavin)

browser/base/content/browser.js

@@ -6721,6 +6721,7 @@ var AugmentTabs = {
 
     // create new menu item
     var undoCloseTabItem = document.createElement("menuitem");
+    undoCloseTabItem.setAttribute("id", "tabContextUndoCloseTab");
     undoCloseTabItem.setAttribute("label", menuLabel);
     undoCloseTabItem.setAttribute("accesskey", menuAccessKey);
     undoCloseTabItem.addEventListener("command", function() { undoCloseTab(0); }, false);