Make XPFragmentBuilder only Builder with access to DstCopy.

src/gpu/effects/GrDashingEffect.cpp

Index: src/gpu/effects/GrDashingEffect.cpp
diff --git a/src/gpu/effects/GrDashingEffect.cpp b/src/gpu/effects/GrDashingEffect.cpp
index b729d0a698357a7028adcd9e344ff8ea97392b03..52e746dc48665429229fbc165f76cbba2b53dfa3 100644
--- a/src/gpu/effects/GrDashingEffect.cpp
+++ b/src/gpu/effects/GrDashingEffect.cpp
@@ -891,7 +891,7 @@ void GLDashingCircleEffect::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
                          args.fTransformsIn, args.fTransformsOut);
 
     // transforms all points so that we can compare them to our test circle
-    GrGLGPFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();
+    GrGLFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();
     fsBuilder->codeAppendf("float xShifted = %s.x - floor(%s.x / %s.z) * %s.z;",
                            dashParams.fsIn(), dashParams.fsIn(), dashParams.fsIn(),
                            dashParams.fsIn());
@@ -1134,7 +1134,7 @@ void GLDashingLineEffect::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
                          args.fTransformsIn, args.fTransformsOut);
 
     // transforms all points so that we can compare them to our test rect
-    GrGLGPFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();
+    GrGLFragmentBuilder* fsBuilder = args.fPB->getFragmentShaderBuilder();
     fsBuilder->codeAppendf("float xShifted = %s.x - floor(%s.x / %s.z) * %s.z;",
                            inDashParams.fsIn(), inDashParams.fsIn(), inDashParams.fsIn(),
                            inDashParams.fsIn());