Make XPFragmentBuilder only Builder with access to DstCopy.

src/gpu/effects/GrConvolutionEffect.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 "GrConvolutionEffect.h"
 #include "gl/GrGLProcessor.h"
 #include "gl/GrGLSL.h"
@@ skipping 51 matching lines @@
                                              "ImageIncrement");
     if (this->useBounds()) {
         fBoundsUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                          kVec2f_GrSLType, kDefault_GrSLPrecision,
                                          "Bounds");
     }
     fKernelUni = builder->addUniformArray(GrGLProgramBuilder::kFragment_Visibility,
                                           kFloat_GrSLType, kDefault_GrSLPrecision,
                                           "Kernel", this->width());
 
-    GrGLFPFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
+    GrGLFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
     SkString coords2D = fsBuilder->ensureFSCoords2D(coords, 0);
 
     fsBuilder->codeAppendf("\t\t%s = vec4(0, 0, 0, 0);\n", outputColor);
 
     int width = this->width();
     const GrGLShaderVar& kernel = builder->getUniformVariable(fKernelUni);
     const char* imgInc = builder->getUniformCStr(fImageIncrementUni);
 
     fsBuilder->codeAppendf("\t\tvec2 coord = %s - %d.0 * %s;\n", coords2D.c_str(), fRadius, imgInc);
 
@@ skipping 153 matching lines @@
     }
 
     bool useBounds = random->nextBool();
     return GrConvolutionEffect::Create(textures[texIdx],
                                        dir,
                                        radius,
                                        kernel,
                                        useBounds,
                                        bounds);
 }