WebSocket(String url, [Object protocols])

Source 

@DomName('WebSocket.WebSocket')
@DocsEditable()
factory WebSocket(String url, [Object protocols]) {
  if (protocols != null) {
    return _blink.BlinkWebSocket.instance.constructorCallback_2_(url, protocols);
  }
  return _blink.BlinkWebSocket.instance.constructorCallback_1_(url);
}