hide setTextEncoding

Bug: skia:
Change-Id: Ia9d3acadc1ef8a9b3c175dba501a5324179d27e9
Reviewed-on: https://skia-review.googlesource.com/c/181566
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
Auto-Submit: Mike Reed <reed@google.com>
9 files changed