Revert of Move DstCopy on gpu into the GrXferProcessor.

src/gpu/GrPipelineBuilder.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrPipelineBuilder_DEFINED
 #define GrPipelineBuilder_DEFINED
 
@@ skipping 84 matching lines @@
         if (!fXPFactory) {
             fXPFactory.reset(GrPorterDuffXPFactory::Create(SkXfermode::kSrc_Mode));
         }
         return fXPFactory.get();
     }
 
     const GrFragmentStage& getColorStage(int idx) const { return fColorStages[idx]; }
     const GrFragmentStage& getCoverageStage(int idx) const { return fCoverageStages[idx]; }
 
     /**
-     * Checks whether the xp will need a copy of the destination to correctly blend.
+     * Checks whether the xp will read the dst pixel color.
+     * TODO: remove when we have dstCpy contained inside of GrXP
      */
-    bool willXPNeedDstCopy(const GrDrawTargetCaps& caps) const;
+    bool willEffectReadDstColor() const;
 
     /**
      * The xfer processor factory.
      */
     const GrXPFactory* setXPFactory(const GrXPFactory* xpFactory) {
         fXPFactory.reset(SkRef(xpFactory));
         return xpFactory;
     }
 
     void setPorterDuffXPFactory(SkXfermode::Mode mode) {
@@ skipping 344 matching lines @@
     mutable GrProcOptInfo fCoverageProcInfo;
     mutable bool fColorProcInfoValid;
     mutable bool fCoverageProcInfoValid;
     mutable GrColor fColorCache;
     mutable GrColor fCoverageCache;
 
     friend class GrPipeline;
 };
 
 #endif