Dawn: update fences to new API.

Bug: skia:11855
Change-Id: I77ed8b93efb1a9d806f6bec3963c57b7ce16fe4d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/397138
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Stephen White <senorblanco@google.com>
1 file changed