Vertex color xform bench

Measures two different strategies for dealing with color space transform
of per-op colors. Assuming we already use vertex colors, is it better to
transform them on the CPU, and use float4 color attributes, or transform
them on the GPU, and use ubyte4 color attributes?

So far, looks like ubyte4 w/GPU transform wins.

Change-Id: If49d75303f669fe7f78af8771af906fa0e872577
Reviewed-on: https://skia-review.googlesource.com/142801
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
3 files changed