043f18f843
Previously we expected the client to provide a set of promotable fields, which worked well for testing. But using a callback gives the client more flexibility (e.g. it would allow field promotability to be computed on demand based on other data). Bug: https://github.com/dart-lang/language/issues/2020 Change-Id: I40683a4c19a17147e86f0faa1339aa025da35229 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/256962 Reviewed-by: Konstantin Shcheglov <scheglov@google.com> Commit-Queue: Paul Berry <paulberry@google.com>