Update several more oval ops to use WriteVertexData

Use shared octagon vertex data, remove some vertex structs
entirely.

Bug: skia:
Change-Id: Ia717bac85de7084a982f0d10d932ea91f04f36f4
Reviewed-on: https://skia-review.googlesource.com/c/169820
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed