hide SkFont::containsText Bug: skia: Change-Id: I197addb0ea1da57083283b30e19e290cdaf8dac6 Reviewed-on: https://skia-review.googlesource.com/c/188581 Reviewed-by: Mike Reed <reed@google.com> Commit-Queue: Mike Reed <reed@google.com> Auto-Submit: Mike Reed <reed@google.com>