transform gradient colors without skcms

This use of skcms kind of sticks out as odd now.
We can do all this using plain old SkConvertPixels.

Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Id416058717359a413fcae63d2ae5c91040440a87
Reviewed-on: https://skia-review.googlesource.com/c/161583
Auto-Submit: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
1 file changed