Line metrics: return all indices in UTF16

Bug: skia:12383
Change-Id: Ibf5521caa8858a7f18fd2717f5f55ff52ffeef54
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/443403
Commit-Queue: Julia Lavrova <jlavrova@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2 files changed