Init digest sets drop for empty glyphs

All empty glyphs can be dropped for all draw types. Have
the digest initializer handle this.

Bug: skia:14065
Change-Id: Ie97aad0df59fbcca35e5050a356406d69a19d376
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/638219
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
1 file changed