RemotePlayback: cancelWatchAvailability() 方法

cancelWatchAvailability()
cancelWatchAvailability(id)

function switchToRemoteUI() {
  // Indicate that the state is 'connecting' or 'connected' to the user.
  // For example, hide the video element as only controls are needed.
  videoElem.style.display = "none";

  // Stop monitoring the availability of remote playback devices.
  videoElem.remote.cancelWatchAvailability();
}