Add wait function to GrVkSecondaryCBDrawContext for semaphores.

Bug: skia:
Change-Id: Icd4875fa8fa495f9ce02135bc0a8c37608ed09df
Reviewed-on: https://skia-review.googlesource.com/c/181661
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
2 files changed