split transformed mask from SDFT

* transformed masks -> GrTransformedMaskSubRun
* GrMaskSubRun is SDFT -> GrSDFTSubRun

There is much duplicate code, which will be cleaned up shortly.

Change-Id: If54e388e89f7db15ddfd4b4354f0a1b4d6f5e36b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/305686
Reviewed-by: Herb Derby <herb@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
3 files changed