Move DstCopy on gpu into the GrXferProcessor.

src/gpu/gl/GrGLGpu.cpp

Index: src/gpu/gl/GrGLGpu.cpp
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index 6d14e7e6c583920215ecda7f6f6100487221d7c4..924a1e0d3acdd1751a9803eb379dd031208981f3 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -1440,10 +1440,8 @@ void GrGLGpu::setupGeometry(const GrPrimitiveProcessor& primProc,
 void GrGLGpu::buildProgramDesc(GrProgramDesc* desc,
                                const GrPrimitiveProcessor& primProc,
                                const GrPipeline& pipeline,
-                               const GrProgramDesc::DescInfo& descInfo,
                                const GrBatchTracker& batchTracker) const {
-    if (!GrGLProgramDescBuilder::Build(desc, primProc, pipeline, descInfo, this,
-                                       batchTracker)) {
+    if (!GrGLProgramDescBuilder::Build(desc, primProc, pipeline, this, batchTracker)) {
         SkDEBUGFAIL("Failed to generate GL program descriptor");
     }
 }