Make XPFragmentBuilder only Builder with access to DstCopy.

src/gpu/gl/GrGLPrimitiveProcessor.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 "GrGLPrimitiveProcessor.h"
 
 #include "builders/GrGLProgramBuilder.h"
@@ skipping 19 matching lines @@
     }
     return combined;
 }
 
 void
 GrGLPrimitiveProcessor::setupColorPassThrough(GrGLGPBuilder* pb,
                                               GrGPInput inputType,
                                               const char* outputName,
                                               const GrGeometryProcessor::Attribute* colorAttr,
                                               UniformHandle* colorUniform) {
-    GrGLGPFragmentBuilder* fs = pb->getFragmentShaderBuilder();
+    GrGLFragmentBuilder* fs = pb->getFragmentShaderBuilder();
     if (kUniform_GrGPInput == inputType) {
         SkASSERT(colorUniform);
         const char* stagedLocalVarName;
         *colorUniform = pb->addUniform(GrGLProgramBuilder::kFragment_Visibility,
                                        kVec4f_GrSLType,
                                        kDefault_GrSLPrecision,
                                        "Color",
                                        &stagedLocalVarName);
         fs->codeAppendf("%s = %s;", outputName, stagedLocalVarName);
     } else if (kAttribute_GrGPInput == inputType) {
@@ skipping 15 matching lines @@
                                                   const SkMatrix& viewMatrix) {
     if (!viewMatrix.isIdentity() && !fViewMatrix.cheapEqualTo(viewMatrix)) {
         SkASSERT(fViewMatrixUniform.isValid());
         fViewMatrix = viewMatrix;
 
         GrGLfloat viewMatrix[3 * 3];
         GrGLGetMatrix<3>(viewMatrix, fViewMatrix);
         pdman.setMatrix3f(fViewMatrixUniform, viewMatrix);
     }
 }