obsolete event is fired when the manifest was found to have become a 404 or 410 page, so the application cache is being deleted.
- Default Action
||EventTarget (DOM element)||The event target (the topmost target in the DOM tree). Read Only.|
||string||The type of event. Read only.|
||boolean||Does the event normally bubble? Read only.|
||boolean||Is it possible to cancel the event? Read only.|