centralize encoding to SkData

Bug: skia:
Change-Id: If3a9a6de54cf76d03e4d159b54b07a4ea6d5cda9
Reviewed-on: https://skia-review.googlesource.com/83020
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Mike Reed <reed@google.com>
3 files changed