Create Vec2ExpressionAnimator

Change-Id: I056eb5ca61c14dd58c2edeadcd122f383094fcb9
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/439976
Commit-Queue: Kyle Carlstrom <kylecarlstrom@google.com>
Commit-Queue: Avinash Parchuri <aparchur@google.com>
Reviewed-by: Avinash Parchuri <aparchur@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
2 files changed