Replace GrOverrideInputFragmentProcessor with a runtime FP

Change-Id: Ife4dcd5627851b2dac1ed05b38c551d5d258e39c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/419797
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
8 files changed