c4f4dcbe6a
This significantly simplifies hierarchies at cost of a few duplications. Change-Id: I72bfe4d2af1fab1cabf6226b102d2bd32b146272 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/441244 Reviewed-by: Brian Wilkerson <brianwilkerson@google.com> Reviewed-by: Paul Berry <paulberry@google.com> Commit-Queue: Konstantin Shcheglov <scheglov@google.com>