Sam Rawlins
ce3b7c2b9c
This adds and tests support for adding file overlays, changing them, and removing them. Work towards https://github.com/dart-lang/sdk/issues/53402 Change-Id: I7939f8199639f7e336cd97515c2f7d48b1d777a0 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/384305 Reviewed-by: Brian Wilkerson <brianwilkerson@google.com> Reviewed-by: Konstantin Shcheglov <scheglov@google.com> Commit-Queue: Samuel Rawlins <srawlins@google.com>