Simplify two more clients of proxy provider (mipped vs. non-mipped)

Bug: skia:
Change-Id: Ic9a2e0e4afe96d916f9054cd7fbd66ee0147719e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/203162
Auto-Submit: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
2 files changed