This is a reland of 0b62a05d9a
Original change's description:
> Add unit test confirming Runtime Blends match native blends.
>
> We perform the same draw operation twice--once with a `setBlendMode`
> based blend, and then once more with `setBlender` and passing SkSL which
> is equivalent to the native blend op. If this test fails, it would
> indicate that Runtime Blends aren't being applied appropriately (or
> perhaps that a GPU's built-in blending modes are cutting corners?).
>
> Change-Id: I4ca1f9ed600d9ec733687cc6de7d3e2eb6e765c9
> Bug: skia:12080
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/428318
> Auto-Submit: John Stiles <johnstiles@google.com>
> Reviewed-by: Mike Reed <reed@google.com>
> Commit-Queue: John Stiles <johnstiles@google.com>
Bug: skia:12080
Change-Id: Idf4297314b133e5bce689a25d53063bff8469fac
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/428676
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
0397ae4e15