Function trapCapturedEvent

docs/external/js/react-dom.development.js:4258–4260

(topLevelType, element)

    trapEventForPluginEventSystem(element, topLevelType, false);
  }
  function trapCapturedEvent(topLevelType, element) {
    trapEventForPluginEventSystem(element, topLevelType, true);
  }

  function trapEventForPluginEventSystem(container, topLevelType, capture) {
    var listener;