Change internal cache to be per-name/face

Goal is to allow callers to pass in names in any order, in any number,
and still get the advantage of the cache.

Change-Id: Iabe6f229c94552df99c13ee4598e17c967946984
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1027318
Reviewed-by: Julia Lavrova <jlavrova@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Julia Lavrova <jlavrova@google.com>
2 files changed