Revert "remove dead code for legacy image encode api"

This reverts commit 41ed7f33792c4c32b8444230b8b59cab5e29e45e.

Reason for revert: Need this in temporarily to navigate Flutter and Fuchsia rolls.

Original change's description:
> remove dead code for legacy image encode api
> 
> Bug: skia:
> Change-Id: Ia90d776946281473c56cd93006df1b523475696a
> Reviewed-on: https://skia-review.googlesource.com/23022
> Reviewed-by: Leon Scroggins <scroggo@google.com>
> Commit-Queue: Mike Reed <reed@google.com>

TBR=scroggo@google.com,reed@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: skia:
Change-Id: I078762fc13de0c455dc6f8a5725d9529af03bffc
Reviewed-on: https://skia-review.googlesource.com/23385
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
3 files changed