This is following the design discussion we had a few months ago.
Change-Id: I48b2e82af33d10b9cd1e599e1b3a4e8e419417c8
Reviewed-on: https://dart-review.googlesource.com/56035
Commit-Queue: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Peter von der Ahé <ahe@google.com>