Round unresolved font blocks to grapheme edges

I had to stage the change with SK_PARAGRAPH_GRAPHEME_EDGES because of
some google3 tests.
Bug: skia:11196

Change-Id: Ic45e43e6c69f649c6bc0fedcc6f303891139b85e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/359566
Commit-Queue: Julia Lavrova <jlavrova@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
4 files changed