1. DomName('Navigator.sendBeacon')
  2. DocsEditable()
  3. Experimental()
bool sendBeacon(String url, Object data)

Source 

@DomName('Navigator.sendBeacon')
@DocsEditable()
@Experimental() // untriaged
bool sendBeacon(String url, Object data) => _blink.BlinkNavigator.instance.sendBeacon_Callback_2_(this, url, data);