Implement all AE grouping modes: character/word/line/all.
-- character grouping was already supported (default mode)
-- for word and line grouping, expand the existing domain mapping logic
to also track cumulative advance and max(ascent) per span, then use
this info to compute anchor point boxes
-- for "all" grouping, the anchor point box coincides with the text box
(https://helpx.adobe.com/after-effects/using/animating-text.html#text_anchor_point_properties)
TBR=
Change-Id: I8564f1349d167d82c31862d8f7e57615cdae0dcf
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/274201
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>