commit: function ES_commit() {
    var searchService = Cc["@mozilla.org/browser/search-service;1"].
                        getService(Ci.nsIBrowserSearchService);
    var currentEngine = this._cloneEngine(searchService.currentEngine);
    for (var i = 0; i < this._ops.length; i++)
      this._ops[i].commit();
    if (this._defaultEngines.some(this._isSameEngine, currentEngine) &&
        !currentEngine.originalEngine.hidden)
      searchService.currentEngine = currentEngine.originalEngine;
  },