Restore cpu execution of async* GMs

Change-Id: Ia0de701ab0aaae4ee6d7631f6df95bf3296f9bdf
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/327177
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
1 file changed