Add halfLeading to TextStyle and StrutStyle: https://github.com/flutter/engine/pull/24668

Change-Id: I5627cb163400880992db622bb887093da92d1cd5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/394969
Commit-Queue: Julia Lavrova <jlavrova@google.com>
Reviewed-by: Julia Lavrova <jlavrova@google.com>
12 files changed