Some group effects (including layer opacity) are not applied upfront,
via an expensive saveLayer, but are deferred until we can determine
whether they can be folded into an atomic draw's paint (to avoid the
extra layer).
At the moment, the MotionTile custom render node drops all pending
paint effects on the floor (ignores |ctx|). Update to apply via the
shader paint.
Also update a couple of related tests to animate opacity.
Change-Id: I1f5cd2459ec81b170749528e8818d0be598a7ca7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/452723
Commit-Queue: Florin Malita <fmalita@google.com>
Reviewed-by: Jorge Betancourt <jmbetancourt@google.com>
18cb4a67d8