Simplify or even skip glyph spacing if possible

Change-Id: Ibcf5db117b338c9a4c0582067e63e98f55e25a3a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/526271
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Julia Lavrova <jlavrova@google.com>
6 files changed