Remove digest() use more specific versions

Remove digest() from the API, and use the more
specific version.

Bug: skia:14065
Change-Id: I6daa4fab7ac38bc974510d733055928e36b58001
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/638160
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
6 files changed