Apply coverage in XP base class when using dst reads

src/gpu/effects/GrCoverageSetOpXP.cpp

 
 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "effects/GrCoverageSetOpXP.h"
 #include "GrCaps.h"
 #include "GrColor.h"
 #include "GrProcessor.h"
 #include "GrProcOptInfo.h"
 #include "gl/GrGLXferProcessor.h"
 #include "gl/builders/GrGLFragmentShaderBuilder.h"
 #include "gl/builders/GrGLProgramBuilder.h"
 
 class CoverageSetOpXP : public GrXferProcessor {
 public:
     static GrXferProcessor* Create(SkRegion::Op regionOp, bool invertCoverage) {
         return SkNEW_ARGS(CoverageSetOpXP, (regionOp, invertCoverage));
     }
 
     ~CoverageSetOpXP() override;
 
     const char* name() const override { return "Coverage Set Op"; }
 
     GrGLXferProcessor* createGLInstance() const override;
 
-    bool hasSecondaryOutput() const override { return false; }
-
     bool invertCoverage() const { return fInvertCoverage; }
 
 private:
     CoverageSetOpXP(SkRegion::Op regionOp, bool fInvertCoverage);
 
     GrXferProcessor::OptFlags onGetOptimizations(const GrProcOptInfo& colorPOI,
                                                  const GrProcOptInfo& coveragePOI,
                                                  bool doesStencilWrite,
                                                  GrColor* color,
                                                  const GrCaps& caps) override;
@@ skipping 198 matching lines @@
 
 GrXPFactory* GrCoverageSetOpXPFactory::TestCreate(SkRandom* random,
                                                   GrContext*,
                                                   const GrCaps&,
                                                   GrTexture*[]) {
     SkRegion::Op regionOp = SkRegion::Op(random->nextULessThan(SkRegion::kLastOp + 1));
     bool invertCoverage = random->nextBool();
     return GrCoverageSetOpXPFactory::Create(regionOp, invertCoverage);
 }