hide (unused) intercepts methods -- for staging migration to SkFont

Bug: skia:
Change-Id: I93a52a9f20fe715dca0393e2c892369e01817de1
Reviewed-on: https://skia-review.googlesource.com/c/172063
Reviewed-by: Florin Malita <fmalita@chromium.org>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
2 files changed