Oval and stroke AA rect now batch

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/bc54fab1a4e5b51628a8c1557c62bc74e078870d

Committed: https://skia.googlesource.com/skia/+/18055afb838a278b5a8436cd51dbfbb688e1e0a0

Review URL: https://codereview.chromium.org/664193002