Callback for the result of the application reputation query.
| aStatus | NS_OK if and only if the query succeeded. If it did, then shouldBlock is meaningful (otherwise it defaults to false). This may be NS_ERROR_FAILURE if the response cannot be parsed, or NS_ERROR_NOT_AVAILABLE if the service has been disabled or is not reachable. |
| aShouldBlock | Whether or not the download should be blocked. |