Add explicit size & null checks to GrVkCommandBuffer::submitPipelineBarriers

Change-Id: I5d39cc692777a662f509b92d2ba104715df1273a
Bug: https://crbug.com/1469231
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/738101
Commit-Queue: Nicolette Prevost <nicolettep@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
1 file changed