SkColorSpaceXformCanvas: simple support for shaders

So far it looks like we can hit the major shader subclasses without
needing to add new calls to SkShader.  Not married to this approach,
but it's a big head start.

I've left out nonlinear gradient types just to keep this CL clear.
Will follow up with them... they won't be interestingly different.

Change-Id: I8711ff464f384d8be1671c139ba10a20502d9c0f
Reviewed-on: https://skia-review.googlesource.com/9742
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
1 file changed