Add swiftshader workaround to resolve full MSAA image in dmsaa RenderPass.

Bug: b/303705884
Change-Id: Ie630c897b739530db1d61b055a9dfee3d03ca539
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/768298
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
3 files changed