Remove SK_IGNORE_SKIMAGE_ONREFENCODED_CHANGE.

All implementers have been updated, so remove the flag and old code.

Change-Id: Ie9747f37dd0ea3f1db682891bcae2496a470bc3a
Reviewed-on: https://skia-review.googlesource.com/128883
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
9 files changed