Return results, so they can be immutable

Change-Id: Ia37e3d6c63a925d956854b355b52ce2ec40f6e2d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1054477
Reviewed-by: Kaylee Lubick <kjlubick@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Mike Reed <mike@reedtribe.org>
10 files changed