Move addOp to SubRun and rename

Change-Id: I2f1a10d2e19e3a57b1c58e2a4fb0171d15c62b7f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/293346
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
3 files changed