Runtime Blend effects always take two input colors--source and
destination--instead of one. This CL adds a new ProgramKind for blend
effects, a new program module (empty for now), and adds a test to
confirm that the signature for blend functions is checked. Currently
these are only accessible via skslc; there's no Runtime Effect API to
create one and the dest color isn't hooked up to anything.
Change-Id: I5272a811d2d76b878cfdf3429efa78c9c8b3fd97
Bug: skia:12080
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/416798
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
f7f36ae077