hide SkImageDeserializer

Bug: skia:
Change-Id: I1cd4e8c626628a3e6426afd7d6bae628d58989c3
Reviewed-on: https://skia-review.googlesource.com/85743
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
6 files changed