Create xfer processor backend.

src/gpu/gl/GrGLProcessor.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLProcessor_DEFINED
 #define GrGLProcessor_DEFINED
 
@@ skipping 99 matching lines @@
         to have an identical processor key as the one that created this GrGLFragmentProcessor.  */
     // TODO update this to pass in GrFragmentProcessor
     virtual void setData(const GrGLProgramDataManager&, const GrProcessor&) {}
 
     static void GenKey(const GrProcessor&, const GrGLCaps&, GrProcessorKeyBuilder*) {}
 
 private:
     typedef GrGLProcessor INHERITED;
 };
 
-class GrGLXferProcessor : public GrGLFragmentProcessor {
-public:
-    GrGLXferProcessor() {}
-    
-    virtual ~GrGLXferProcessor() {}
-
-private:
-    typedef GrGLFragmentProcessor INHERITED;
-};
-
 #endif