Replace fWillReadFragmentPosition with a bitfield

src/effects/SkLightingImageFilter.cpp

 /*
  * Copyright 2012 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkLightingImageFilter.h"
 #include "SkBitmap.h"
 #include "SkColorPriv.h"
@@ skipping 1639 matching lines @@
                                    BoundaryMode boundaryMode,
                                    const SkIRect* srcBounds)
     : INHERITED(texture, GrCoordTransform::MakeDivByTextureWHMatrix(texture))
     , fLight(light)
     , fSurfaceScale(surfaceScale)
     , fFilterMatrix(matrix)
     , fBoundaryMode(boundaryMode)
     , fDomain(create_domain(texture, srcBounds, GrTextureDomain::kDecal_Mode)) {
     fLight->ref();
     if (light->requiresFragmentPosition()) {
-        this->setWillReadFragmentPosition();
+        this->enableBuiltInState(kFragmentPosition_BuiltInState);
     }
 }
 
 GrLightingEffect::~GrLightingEffect() {
     fLight->unref();
 }
 
 bool GrLightingEffect::onIsEqual(const GrFragmentProcessor& sBase) const {
     const GrLightingEffect& s = sBase.cast<GrLightingEffect>();
     return fLight->isEqual(*s.fLight) &&
@@ skipping 447 matching lines @@
 
     fragBuilder->codeAppendf("%s(%s)", fLightColorFunc.c_str(), surfaceToLight);
 }
 
 #endif
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkLightingImageFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkDiffuseLightingImageFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkSpecularLightingImageFilter)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END