The obsolete event is fired when the manifest was found to have become a 404 or 410 page, so the application cache is being deleted.
General info
- Specification
 - Offline
 - Interface
 - Event
 - Bubbles
 - No
 - Cancelable
 - No
 - Target
 - applicationCache
 - Default Action
 - None
 
Properties
| Property | Type | Description | 
target | 
   EventTarget (DOM element) | The event target (the topmost target in the DOM tree). Read Only. | 
type | 
   string | The type of event. Read only. | 
canBubble | 
   boolean | Does the event normally bubble? Read only. | 
cancelable | 
   boolean | Is it possible to cancel the event? Read only. |