Web Storage IDL tests

[PrimaryGlobal]
interface Window {
};

interface Event {
};

interface EventInit {
};

interface Storage {
  readonly attribute unsigned long length;
  DOMString? key(unsigned long index);
  getter DOMString? getItem(DOMString key);
  setter void setItem(DOMString key, DOMString value);
  deleter void removeItem(DOMString key);
  void clear();
};
[NoInterfaceObject]
interface WindowSessionStorage {
  readonly attribute Storage sessionStorage;
};
Window implements WindowSessionStorage;
[NoInterfaceObject]
interface WindowLocalStorage {
  readonly attribute Storage localStorage;
};
Window implements WindowLocalStorage;
[Constructor(DOMString type, optional StorageEventInit eventInitDict)]
interface StorageEvent : Event {
  readonly attribute DOMString? key;
  readonly attribute DOMString? oldValue;
  readonly attribute DOMString? newValue;
  readonly attribute DOMString url;
  readonly attribute Storage? storageArea;
};

dictionary StorageEventInit : EventInit {
  DOMString? key;
  DOMString? oldValue;
  DOMString? newValue;
  DOMString url;
  Storage? storageArea;
};