Replace fWillReadFragmentPosition with a bitfield

src/gpu/effects/GrOvalEffect.cpp

Index: src/gpu/effects/GrOvalEffect.cpp
diff --git a/src/gpu/effects/GrOvalEffect.cpp b/src/gpu/effects/GrOvalEffect.cpp
index 3e6287bbd2f24a1d2609ef6ada84a336ea172a5f..9b030f6a256b8a13336ca49e6fd4eef3a22cb29c 100644
--- a/src/gpu/effects/GrOvalEffect.cpp
+++ b/src/gpu/effects/GrOvalEffect.cpp
@@ -65,7 +65,7 @@ CircleEffect::CircleEffect(GrPrimitiveEdgeType edgeType, const SkPoint& c, SkSca
     , fRadius(r)
     , fEdgeType(edgeType) {
     this->initClassID<CircleEffect>();
-    this->setWillReadFragmentPosition();
+    this->enableBuiltInState(kFragmentPosition_BuiltInState);
 }
 
 bool CircleEffect::onIsEqual(const GrFragmentProcessor& other) const {
@@ -232,7 +232,7 @@ EllipseEffect::EllipseEffect(GrPrimitiveEdgeType edgeType, const SkPoint& c, SkS
     , fRadii(SkVector::Make(rx, ry))
     , fEdgeType(edgeType) {
     this->initClassID<EllipseEffect>();
-    this->setWillReadFragmentPosition();
+    this->enableBuiltInState(kFragmentPosition_BuiltInState);
 }
 
 bool EllipseEffect::onIsEqual(const GrFragmentProcessor& other) const {