获取document对象
deleteListener
通过lastProps/nextProps判断删除/新增事件
_updateDOMProperties
有nextProps属性(mountComponent、updateComponent)
无nextProps(unmountComponent中,删除注册的listener,防止内存泄漏)
判断事件捕获/冒泡
listenTo
trapCapturedEvent
捕获
enqueuePutListener
冒泡
trapBubbledEvent