69cf1dfa5c
based off https://github.com/lrhn/platform.dart/blob/18312f7a48586e92a196c27c1001a1e57297f44e/migration-guide.md Change-Id: I29d3227fdf6b01faf6ddad4133aac9079ec3b994 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/335327 Commit-Queue: Keerti Parthasarathy <keertip@google.com> Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>