eb3fdd7683
Avoids inadvertently covering up data races. TEST=tsan Change-Id: Icb001391638b9f467145cf889363d47527933cd9 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/446988 Reviewed-by: Alexander Aprelev <aam@google.com> Commit-Queue: Ryan Macnak <rmacnak@google.com>