onDeleted property

VoidCallback onDeleted

Called when the user taps the deleteIcon to delete the chip.

If null, the delete button will not appear on the chip.

The chip will not automatically remove itself: this just tells the app that the user tapped the delete button. In order to delete the chip, you have to do something similar to the following sample:

This sample shows how to use onDeleted to remove an entry when the delete button is tapped. 
class Actor {
  const Actor(this.name, this.initials);
  final String name;
  final String initials;
}

class CastList extends StatefulWidget {
  @override
  State createState() => CastListState();
}

class CastListState extends State<CastList> {
  final List<Actor> _cast = <Actor>[
    const Actor('Aaron Burr', 'AB'),
    const Actor('Alexander Hamilton', 'AH'),
    const Actor('Eliza Hamilton', 'EH'),
    const Actor('James Madison', 'JM'),
  ];

  Iterable<Widget> get actorWidgets sync* {
    for (Actor actor in _cast) {
      yield Padding(
        padding: const EdgeInsets.all(4.0),
        child: Chip(
          avatar: CircleAvatar(child: Text(actor.initials)),
          label: Text(actor.name),
          onDeleted: () {
            setState(() {
              _cast.removeWhere((Actor entry) {
                return entry.name == actor.name;
              });
            });
          },
        ),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Wrap(
      children: actorWidgets.toList(),
    );
  }
}

// ...

@override
Widget build(BuildContext context) {
  return CastList();
}

Implementation 

VoidCallback get onDeleted;