Add a single-pass tessellation Op for convex fills

Bug: skia:10419
Change-Id: I0592adc43c1e426795fce133c37844ea7530058b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/416979
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
5 files changed