[skottie] Add support for scale and rotation text animators

The interesting bit here is a change in glyph positioning:
AE text animator transforms are to be applied relative to the glyph position.

To support this behavior, update Shaper to externalize glyph positioning
when in fragmented mode.  I.e. instead of baking glyph positions in blobs,
apply them at the scene graph transform level (such that they compose with
animated transforms correctly).

Change-Id: I9aeb5e6f8c1ec1a2c8b5351e8fc2a73d4bdf5cad
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/217556
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
1 file changed