embed TransformMaskVertexFiller in TransformMaskSubRuns

Change-Id: Ia35ebf64233bfd5aeb8d9719efe4bdf48eaba0e9
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/501336
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
1 file changed