tree f56226671d8f06c69aa9258ae59d63fd8bdd2773
parent 24b38df72430d7e21cb4257828580becb9a39c72
author Mike Fairhurst <mfairhurst@google.com> 1597946861 -0700
committer Mike Fairhurst <mfairhurst@google.com> 1597946861 -0700

Remove unnecessary dart:async import.

With the version constraint excluding 2.0, the import is not necessary.