Make GrSurfaceProxy derive from GrNonAtomicRef and remove GrIORefProxy.

Also, expose GrNonAtomicRef's ref count. Since it's non-atomic and not
thread-safe it seems fine.

Change-Id: I5cf48e60d32094354955b2614cfeebbb4c1ecf2a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/238059
Auto-Submit: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
11 files changed