No one could remember why this code was in a separate repo, and
checking it in to the SDK repo will make eliminating the
flutter buildroot repo a tiny bit easier.
TEST=It builds.
Change-Id: Ia34ca0c284fee1dd1734f45ef7acb9dd5cde808c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/342083
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>
Reviewed-by: Brian Quinlan <bquinlan@google.com>