Make XPFragmentBuilder only Builder with access to DstCopy.

src/gpu/effects/GrSimpleTextureEffect.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrSimpleTextureEffect.h"
 #include "GrInvariantOutput.h"
 #include "GrTexture.h"
 #include "gl/GrGLCaps.h"
 #include "gl/GrGLProcessor.h"
 #include "gl/GrGLSL.h"
 #include "gl/GrGLTexture.h"
 #include "gl/builders/GrGLProgramBuilder.h"
 
 class GrGLSimpleTextureEffect : public GrGLFragmentProcessor {
 public:
     GrGLSimpleTextureEffect(const GrProcessor&) {}
 
     virtual void emitCode(GrGLFPBuilder* builder,
                           const GrFragmentProcessor& fp,
                           const char* outputColor,
                           const char* inputColor,
                           const TransformedCoordsArray& coords,
                           const TextureSamplerArray& samplers) override {
-        GrGLFPFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
+        GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
         fsBuilder->codeAppendf("\t%s = ", outputColor);
         fsBuilder->appendTextureLookupAndModulate(inputColor,
                                                   samplers[0],
                                                   coords[0].c_str(),
                                                   coords[0].getType());
         fsBuilder->codeAppend(";\n");
     }
 
 private:
     typedef GrGLFragmentProcessor INHERITED;
@@ skipping 38 matching lines @@
 
     static const GrCoordSet kCoordSets[] = {
         kLocal_GrCoordSet,
         kDevice_GrCoordSet
     };
     GrCoordSet coordSet = kCoordSets[random->nextULessThan(SK_ARRAY_COUNT(kCoordSets))];
 
     const SkMatrix& matrix = GrTest::TestMatrix(random);
     return GrSimpleTextureEffect::Create(textures[texIdx], matrix, coordSet);
 }