Revert of use conics for ovals and roundrects (patchset #1 id:1 of https://codereview.chromium.org/817283005/)

Reason for revert:
need fix in edgebuilder+aa

Original issue's description:
> use conics for ovals and roundrects
>
> adapted from https://codereview.chromium.org/831313002/
>
> BUG=skia:
> TBR=
>
> Committed: https://skia.googlesource.com/skia/+/2bf1c4d58b84c73c6421edcb25e3afb4971da200

TBR=reed@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/840573002
5 files changed