Implement SkBlender support in SkVM.

A lot of the SkVM-related setup was already hooked up in This CL finishes the job by hooking up
the SkPaint's SkBlender field to SkVM, and adds various checks
throughout Skia's software drawing code that can detect the presence of
an SkBlender.

Since only SkVM knows how to render an SkBlender correctly, we now need
to avoid the legacy blitter and RasterPipeline blitter whenever an
SkBlender is present on the paint. This CL fixes the cases that I've
found so far, while testing rendering with ovals and images. I'm sure
there are more cases lurking; these will be uncovered and dealt with in
future CLs.

Change-Id: I1a7b3d6625352b3cba8e4f8d4c61129d08ac6ae7
Bug: skia:12080
Commit-Queue: John Stiles <>
Auto-Submit: John Stiles <>
Reviewed-by: Mike Reed <>
Reviewed-by: Brian Osman <>
7 files changed