SkImageEncoder::* going away

Approval from https://review.skia.org/5006
TBR=reed@google.com

Change-Id: I43d1a24fa3e924b3c24b224f2451ab990b440dc8
Reviewed-on: https://skia-review.googlesource.com/5413
Reviewed-by: Hal Canary <halcanary@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
5 files changed