Cherry-pick 'rm ok' to skqp/dev.

Seems that https://skia-review.googlesource.com/c/skia/+/117086 depends
on this CL. Original description below.

-----

rm ok

I'm not really using it much anymore.
Time to dedup and fold its ideas into DM.

No-Tree-Checks: true
No-Try: true
No-Presubmit: true
Change-Id: I40a238c9083460e1b7aee459757f867dfd3d79af
Reviewed-On: https://skia-review.googlesource.com/107800
Reviewed-By: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/117728
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Ben Wagner <benjaminwagner@google.com>
8 files changed