Revert of Revert of Move DstCopy on gpu into the GrXferProcessor.

src/gpu/effects/GrCoverageSetOpXP.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrCoverageSetOpXP_DEFINED
 #define GrCoverageSetOpXP_DEFINED
 
@@ skipping 11 matching lines @@
 class GrCoverageSetOpXP : public GrXferProcessor {
 public:
     static GrXferProcessor* Create(SkRegion::Op regionOp, bool invertCoverage) {
         return SkNEW_ARGS(GrCoverageSetOpXP, (regionOp, invertCoverage));
     }
 
     ~GrCoverageSetOpXP() SK_OVERRIDE;
 
     const char* name() const SK_OVERRIDE { return "Coverage Set Op"; }
 
-    void getGLProcessorKey(const GrGLCaps& caps, GrProcessorKeyBuilder* b) const SK_OVERRIDE;
-
     GrGLXferProcessor* createGLInstance() const SK_OVERRIDE;
 
     bool hasSecondaryOutput() const SK_OVERRIDE { return false; }
 
     GrXferProcessor::OptFlags getOptimizations(const GrProcOptInfo& colorPOI,
                                                const GrProcOptInfo& coveragePOI,
                                                bool doesStencilWrite,
                                                GrColor* color,
                                                const GrDrawTargetCaps& caps) SK_OVERRIDE;
 
     void getBlendInfo(GrXferProcessor::BlendInfo* blendInfo) const SK_OVERRIDE;
 
     bool invertCoverage() const { return fInvertCoverage; }
 
 private:
     GrCoverageSetOpXP(SkRegion::Op regionOp, bool fInvertCoverage);
 
+    void onGetGLProcessorKey(const GrGLCaps& caps, GrProcessorKeyBuilder* b) const SK_OVERRIDE;
+
     bool onIsEqual(const GrXferProcessor& xpBase) const SK_OVERRIDE {
         const GrCoverageSetOpXP& xp = xpBase.cast<GrCoverageSetOpXP>();
         return (fRegionOp == xp.fRegionOp &&
                 fInvertCoverage == xp.fInvertCoverage);
     }
 
     SkRegion::Op fRegionOp;
     bool         fInvertCoverage;
 
     typedef GrXferProcessor INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 class GrCoverageSetOpXPFactory : public GrXPFactory {
 public:
     static GrXPFactory* Create(SkRegion::Op regionOp, bool invertCoverage = false);
 
-    GrXferProcessor* createXferProcessor(const GrProcOptInfo& colorPOI,
-                                         const GrProcOptInfo& coveragePOI) const SK_OVERRIDE;
-
     bool supportsRGBCoverage(GrColor knownColor, uint32_t knownColorFlags) const SK_OVERRIDE {
         return true;
     }
 
     bool canApplyCoverage(const GrProcOptInfo& colorPOI,
                           const GrProcOptInfo& coveragePOI) const SK_OVERRIDE {
         return true;
     }
 
     bool canTweakAlphaForCoverage() const SK_OVERRIDE { return false; }
 
     void getInvariantOutput(const GrProcOptInfo& colorPOI, const GrProcOptInfo& coveragePOI,
                             GrXPFactory::InvariantOutput*) const SK_OVERRIDE;
 
-    bool willReadDst() const SK_OVERRIDE { return false; }
-
 private:
     GrCoverageSetOpXPFactory(SkRegion::Op regionOp, bool invertCoverage);
 
+    GrXferProcessor* onCreateXferProcessor(const GrProcOptInfo& colorPOI,
+                                           const GrProcOptInfo& coveragePOI,
+                                           const GrDeviceCoordTexture* dstCopy) const SK_OVERRIDE;
+
+    bool willReadDstColor() const SK_OVERRIDE { return false; }
+
     bool onIsEqual(const GrXPFactory& xpfBase) const SK_OVERRIDE {
         const GrCoverageSetOpXPFactory& xpf = xpfBase.cast<GrCoverageSetOpXPFactory>();
         return fRegionOp == xpf.fRegionOp;
     }
 
     GR_DECLARE_XP_FACTORY_TEST;
 
     SkRegion::Op fRegionOp;
     bool         fInvertCoverage;
 
     typedef GrXPFactory INHERITED;
 };
 #endif