This is an internal helper interface for communication between the
main thread and the dbservice worker thread. It is called for each
lookup to provide a set of possible results, which the main thread
may need to expand using an nsIUrlClassifierCompleter.
The lookup process is complete.
| results | If this parameter is null, there were no results found. If not, it contains an array of nsUrlClassifierEntry objects with possible matches. The callee is responsible for freeing this array. |