Remove willReadDst from GrFragmentProcessor.

src/gpu/GrProcOptInfo.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 "GrProcOptInfo.h"
 
 #include "GrFragmentProcessor.h"
@@ skipping 30 matching lines @@
     fInOut.reset(out);
     this->internalCalc(stages, stageCount, false);
 }
 
 void GrProcOptInfo::internalCalc(const GrFragmentStage* stages,
                                  int stageCount,
                                  bool initWillReadFragmentPosition) {
     fFirstEffectStageIndex = 0;
     fInputColorIsUsed = true;
     fInputColor = fInOut.color();
-    fReadsDst = false;
     fReadsFragPosition = initWillReadFragmentPosition;
 
     for (int i = 0; i < stageCount; ++i) {
         const GrFragmentProcessor* processor = stages[i].processor();
         fInOut.resetWillUseInputColor();
         processor->computeInvariantOutput(&fInOut);
         SkDEBUGCODE(fInOut.validate());
         if (!fInOut.willUseInputColor()) {
             fFirstEffectStageIndex = i;
             fInputColorIsUsed = false;
             // Reset these since we don't care if previous stages read these values
-            fReadsDst = false;
             fReadsFragPosition = initWillReadFragmentPosition;
         }
-        if (processor->willReadDstColor()) {
-            fReadsDst = true;
-        }
         if (processor->willReadFragmentPosition()) {
             fReadsFragPosition = true;
         }
         if (kRGBA_GrColorComponentFlags == fInOut.validFlags()) {
             fFirstEffectStageIndex = i + 1;
             fInputColor = fInOut.color();
             fInputColorIsUsed = true;
             // Since we are clearing all previous color stages we are in a state where we have found
             // zero stages that don't multiply the inputColor.
             fInOut.resetNonMulStageFound();
             // Reset these since we don't care if previous stages read these values
-            fReadsDst = false;
             fReadsFragPosition = initWillReadFragmentPosition;
         }
     }
 }