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

src/gpu/gl/builders/GrGLProgramBuilder.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 "GrGLProgramBuilder.h"
 #include "gl/GrGLProgram.h"
 #include "gl/GrGLSLPrettyPrint.h"
@@ skipping 38 matching lines @@
 
 const int GrGLProgramBuilder::kVarsPerBlock = 8;
 
 GrGLProgram* GrGLProgramBuilder::CreateProgram(const DrawArgs& args, GrGLGpu* gpu) {
     // create a builder.  This will be handed off to effects so they can use it to add
     // uniforms, varyings, textures, etc
     SkAutoTDelete<GrGLProgramBuilder> builder(CreateProgramBuilder(args, gpu));
 
     GrGLProgramBuilder* pb = builder.get();
 
-    // emit code to read the dst copy texture, if necessary
-    if (GrGLFragmentShaderBuilder::kNoDstRead_DstReadKey != pb->header().fDstReadKey &&
-        !gpu->glCaps().fbFetchSupport()) {
-        pb->fFS.emitCodeToReadDstTexture();
-    }
-
     // TODO: Once all stages can handle taking a float or vec4 and correctly handling them we can
     // seed correctly here
     GrGLSLExpr4 inputColor;
     GrGLSLExpr4 inputCoverage;
 
     pb->emitAndInstallProcs(&inputColor, &inputCoverage);
 
     return pb->finalize();
 }
 
@@ skipping 420 matching lines @@
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 GrGLInstalledFragProcs::~GrGLInstalledFragProcs() {
     int numProcs = fProcs.count();
     for (int e = 0; e < numProcs; ++e) {
         SkDELETE(fProcs[e]);
     }
 }