Revert of Revert of 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 dd55abb0a6331d41477e1aa4a1b6e3f0b1906173..6419aa6b522b15e6f8ab31cc9f6ff01ec2fa325d 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -1451,10 +1451,8 @@
 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");
     }
 }