We'd really like to converge on SkRGBA4f everywhere. This CL continues
to store GrColor4f in the GPU backend, but changes the constantColor
optimization logic to use SkPMColor4f.
GrColor[4f] have "unknown" alpha type, but in this context, they are
nearly always premul, so let's take advantage of our SkRGBA4f type
safety. We lose some of the semantic benefits and helpers that are
present in GrColor4f (OpaqueWhite, TransparentBlack).
The biggest thing that would probably help is a direct path to/from
bytes (GrColor).
Bug: skia:
Change-Id: Ic0838ad3f95d207163b3af51e5f5cf6f499c2047
Reviewed-on: https://skia-review.googlesource.com/157840
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1d5b598c4e