Revert "clean up (partially) colortable api"

Revert "clean up (partially) colortable api"

This reverts commit 2e491a6a113c5e16a3b7bede5fa6f588deeb928d.

Reason for revert: Windows unit tests failing?

Original change's description:
> clean up (partially) colortable api
>
> Needs this to land: https://codereview.chromium.org/2789853002/
>
> Bug: skia:
> Change-Id: I38d916a546b7fa64d000d973e695ddda24a589e7
> Reviewed-on: https://skia-review.googlesource.com/10600
> Commit-Queue: Mike Reed <reed@google.com>
> Reviewed-by: Matt Sarett <msarett@google.com>
>

TBR=msarett@google.com,scroggo@google.com,reed@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I626e7edfcea82576a440dcaa851a04cedee6233f
Reviewed-on: https://skia-review.googlesource.com/10966
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>