Remove canTweakAlphaForCoverage from XP's since batch reads flag.

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 "GrBatch.h"
@@ skipping 99 matching lines @@
     fPipelineBuilder = pipelineBuilder;
     if (NULL != pipelineBuilder) {
         fColorEffectCnt = pipelineBuilder->numColorFragmentStages();
         fCoverageEffectCnt = pipelineBuilder->numCoverageFragmentStages();
         SkDEBUGCODE(++pipelineBuilder->fBlockEffectRemovalCnt;)
     }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
-// Some blend modes allow folding a fractional coverage value into the color's alpha channel, while
-// others will blend incorrectly.
-bool GrPipelineBuilder::canTweakAlphaForCoverage() const {
-    return this->getXPFactory()->canTweakAlphaForCoverage();
-}
-
-////////////////////////////////////////////////////////////////////////////////
-
 GrPipelineBuilder::~GrPipelineBuilder() {
     SkASSERT(0 == fBlockEffectRemovalCnt);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 bool GrPipelineBuilder::willBlendWithDst(const GrPrimitiveProcessor* pp) const {
     this->calcColorInvariantOutput(pp);
     this->calcCoverageInvariantOutput(pp);
     
@@ skipping 39 matching lines @@
 void GrPipelineBuilder::calcCoverageInvariantOutput(GrColor coverage) const {
     if (!fCoverageProcInfoValid || coverage != fCoverageCache) {
         GrColorComponentFlags flags = kRGBA_GrColorComponentFlags;
         fCoverageProcInfo.calcWithInitialValues(fCoverageStages.begin(),
                                                 this->numCoverageFragmentStages(), coverage, flags,
                                                 true);
         fCoverageProcInfoValid = true;
         fCoverageCache = coverage;
     }
 }