Remove unsized gl stencil support.

We don't believe this is needed anymore and was mostly here to support
old desktop GL

Bug: skia:10727
Change-Id: Iab35ec7d6ed64d817aed57c38864932cc417c68e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/321541
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
3 files changed