Use OpenGL sampler objects when available.

Bug: skia:8471
Change-Id: Ida3d08aa72772b8bbd08707048182bee5d27407c
Reviewed-on: https://skia-review.googlesource.com/c/163123
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
7 files changed