Make Metal render loop more stable

Bug: skia:8737
Change-Id: Ib825e5f0c9502692cbecc60fbb68d0d1a2bc635f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/208672
Auto-Submit: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
2 files changed