Revert of Move DstCopy on gpu into the GrXferProcessor.

src/gpu/GrPipelineBuilder.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrPipelineBuilder.h"
 
 #include "GrBlend.h"
@@ skipping 83 matching lines @@
 
     // The coverage isn't actually white, its unknown, but this will produce the same effect
     // TODO we want to cache the result of this call, but we can probably clean up the interface
     // so we don't have to pass in a seemingly known coverage
     this->calcCoverageInvariantOutput(GrColor_WHITE);
     return this->getXPFactory()->canApplyCoverage(fColorProcInfo, fCoverageProcInfo);
 }
 
 //////////////////////////////////////////////////////////////////////////////s
 
-bool GrPipelineBuilder::willXPNeedDstCopy(const GrDrawTargetCaps& caps) const {
-    return this->getXPFactory()->willNeedDstCopy(caps);
+bool GrPipelineBuilder::willEffectReadDstColor() const {
+    return this->getXPFactory()->willReadDst();
 }
 
 void GrPipelineBuilder::AutoRestoreEffects::set(GrPipelineBuilder* pipelineBuilder) {
     if (fPipelineBuilder) {
         int m = fPipelineBuilder->numColorStages() - fColorEffectCnt;
         SkASSERT(m >= 0);
         fPipelineBuilder->fColorStages.pop_back_n(m);
 
         int n = fPipelineBuilder->numCoverageStages() - fCoverageEffectCnt;
         SkASSERT(n >= 0);
@@ skipping 74 matching lines @@
 void GrPipelineBuilder::calcCoverageInvariantOutput(GrColor coverage) const {
     if (!fCoverageProcInfoValid || coverage != fCoverageCache) {
         GrColorComponentFlags flags = kRGBA_GrColorComponentFlags;
         fCoverageProcInfo.calcWithInitialValues(fCoverageStages.begin(),
                                                 this->numCoverageStages(), coverage, flags,
                                                 true);
         fCoverageProcInfoValid = true;
         fCoverageCache = coverage;
     }
 }