function handleUndoRedo(treeOutline)
        {
            if (WebInspector.KeyboardShortcut.eventHasCtrlOrMeta(event) && !event.shiftKey && event.keyIdentifier === "U+005A") { // Z key
                treeOutline.target().domModel.undo(this._updateSidebars.bind(this));
                event.handled = true;
                return;
            }

            var isRedoKey = WebInspector.isMac() ? event.metaKey && event.shiftKey && event.keyIdentifier === "U+005A" : // Z key
                                                   event.ctrlKey && event.keyIdentifier === "U+0059"; // Y key
            if (isRedoKey) {
                treeOutline.target().domModel.redo(this._updateSidebars.bind(this));
                event.handled = true;
            }
        }
@param {!WebInspector.ElementsTreeOutline} treeOutline
@this {WebInspector.ElementsPanel}