Add SkRuntimeBlender class.

This class is returned by SkRuntimeEffect::makeBlender when a runtime
blend is returned. SkRuntimeBlendBuilder is also added as a convenience
class to simplify creation and uniform setup.

Our ability to add tests is limited in this CL because the SkPaint does
not contain an SkBlender yet. We do have one test which builds an
SkBlender, but there's not much we can do with it. Testing will be
bulked up in the next CL.

Change-Id: Ib2d7d04186690ec0d2238fc990a19d9e6b786ce3
Bug: skia:12080
Commit-Queue: John Stiles <>
Auto-Submit: John Stiles <>
Reviewed-by: Brian Osman <>
3 files changed