Hide the filterquality enum

Change-Id: I1d25c2f04d86374f64319a74effa2144f7d63fdd
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/430423
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed