: function () {
if (this._observer) {
this._makeContentListenersAlwaysNotify();
this._observer.disconnect();
this._observer.observe(this.node, {
childList: true,
attributes: true,
subtree: true
});
var root = this.domApi.getOwnerRoot();
var host = root && root.host;
if (host && Polymer.dom(host).observer) {
Polymer.dom(host).observer.enableShadowAttributeTracking();
}
}
},
_makeContentListenersAlwaysNotify: function () {
for (var i = 0, h; i < this._listeners.length; i++) {
h = this._listeners[i];
h._always