Expand the core animator logic to return whether the computed value is
changing on each tick. Also rename tick/onTick -> seek/onSeek to better
reflect Skottie semantics.
This information allows us to skip adapter updates for static/hold
animation segments.
This effectively hoists some of the scene graph lazy-update logic to the
Skottie model level, and culls unneeded conversions (e.g. we were
converting ShapeValue -> SkPath on every tick, even when the shape was
not changing).
TBR=
Change-Id: I1ea4e19ae8f993d659826269de6b0465fec70189
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/279816
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
0147de41c4