add SkFontPriv.h

Bug: skia:2664
Change-Id: I1751aee25c64880e528432441be7fa6129fc1e0f
Reviewed-on: https://skia-review.googlesource.com/c/168260
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed