Update GrAARectEffect to use a child FP.

We are updating FPs to receive their input via a child FP where
possible, instead of relying on the input color.

Change-Id: I7eed35821024de9dbb6aecceeef02f391aa5ad88
Bug: skia:10217
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/294298
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
diff --git a/src/gpu/effects/GrConvexPolyEffect.cpp b/src/gpu/effects/GrConvexPolyEffect.cpp
index 82de90e..efcfbb3 100644
--- a/src/gpu/effects/GrConvexPolyEffect.cpp
+++ b/src/gpu/effects/GrConvexPolyEffect.cpp
@@ -167,7 +167,7 @@
     if (GrClipEdgeType::kHairlineAA == edgeType){
         return nullptr;
     }
-    return GrAARectEffect::Make(edgeType, rect);
+    return GrAARectEffect::Make(/*inputFP=*/nullptr, edgeType, rect);
 }
 
 GrConvexPolyEffect::~GrConvexPolyEffect() {}