Remove clamping of kPlus with F16 configs

The most common use-case for F16 is to draw things that are explicitly
outside of [0,1]. We can't prevent out-of-range values in general, users
could just draw out-of-range content in src mode. We've decided that
it's best to avoid surprising behavior, and trust the user in these
situations.

This effectively reverts https://skia-review.googlesource.com/c/skia/+/48183

Bug: skia:
Change-Id: I71c2dd925c567e2862d96ab70c752f19245a69c4
Reviewed-on: https://skia-review.googlesource.com/140500
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/src/gpu/effects/GrCoverageSetOpXP.h b/src/gpu/effects/GrCoverageSetOpXP.h
index cf91848..e8bc5a2 100644
--- a/src/gpu/effects/GrCoverageSetOpXP.h
+++ b/src/gpu/effects/GrCoverageSetOpXP.h
@@ -37,13 +37,11 @@
     sk_sp<const GrXferProcessor> makeXferProcessor(const GrProcessorAnalysisColor&,
                                                    GrProcessorAnalysisCoverage,
                                                    bool hasMixedSamples,
-                                                   const GrCaps&,
-                                                   GrPixelConfigIsClamped) const override;
+                                                   const GrCaps&) const override;
 
     AnalysisProperties analysisProperties(const GrProcessorAnalysisColor&,
                                           const GrProcessorAnalysisCoverage&,
-                                          const GrCaps&,
-                                          GrPixelConfigIsClamped) const override {
+                                          const GrCaps&) const override {
         return AnalysisProperties::kIgnoresInputColor;
     }