Move creation of GrProgramDesc to GrCaps-derived classes

We need a means of creating GrProgramDescs pre-flush w/o needing to know the specific backend in play.

Bug: skia:9455
Change-Id: Iac14ff8eda262ee6d2ad666c5d2e27e7a375c210
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/256698
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
35 files changed