[Global=Window, Exposed=Window]
interface Window {
};

partial interface Window {
  unsigned long requestIdleCallback(IdleRequestCallback callback,
                                    optional IdleRequestOptions options);
  void          cancelIdleCallback(unsigned long handle);
};

dictionary IdleRequestOptions {
  unsigned long timeout;
};

[Exposed=Window] interface IdleDeadline {
  DOMHighResTimeStamp timeRemaining();
  readonly attribute boolean didTimeout;
};

callback IdleRequestCallback = void (IdleDeadline deadline);