Only support SkVertices in GrDrawVerticesOp and GrRenderTargetContext

Allow overriding the primitive type at draw time, so everyone can
funnel through the same code path. Simplifies the color array type
logic, and saves one memcpy (of indices) in the drawWireframe case.

Bug: skia:
Change-Id: I46653d34169842b9b5304cff48d804b2a9ace529
Reviewed-on: https://skia-review.googlesource.com/17783
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
5 files changed