Revert "sksl fragment processor support"

This reverts commit ccf59917d3fe7aaf59de714acfbd0596503f324f.

Reason for revert: breaking iOS bots

Original change's description:
> sksl fragment processor support
> 
> Bug: skia:
> Change-Id: Ia3b0305c2b0c78074303831f628fb01852b90d34
> Reviewed-on: https://skia-review.googlesource.com/17843
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
> Reviewed-by: Ben Wagner <benjaminwagner@google.com>
> Reviewed-by: Mike Klein <mtklein@google.com>

TBR=mtklein@google.com,benjaminwagner@google.com,ethannicholas@google.com

Change-Id: I0a33060c7c42c7b44c5c13d443ac42958291c2f1
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/20962
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
54 files changed