SkImageEncoder::* going away

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

Change-Id: Ib5fb1b624594598e2316f9247069ecd207d7a974
Reviewed-on: https://skia-review.googlesource.com/5751
Reviewed-by: Hal Canary <halcanary@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
5 files changed