Revert concave AAA

BUG=skia:6131
TBR=reed@google.com,caryclark@google.com

Change-Id: Ib580a4fb9023f43518a3d89cd70bf2589ad02bb6
Reviewed-on: https://skia-review.googlesource.com/7200
Commit-Queue: Yuqian Li <liyuqian@google.com>
Reviewed-by: Yuqian Li <liyuqian@google.com>
2 files changed