Add XferProcessor factory in GrPaint and GrDrawState.

src/gpu/GrProcOptInfo.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrProcOptInfo_DEFINED
 #define GrProcOptInfo_DEFINED
 
@@ skipping 17 matching lines @@
         , fInputColor(0)
         , fRemoveVertexAttrib(false)
         , fReadsDst(false) {}
 
     void calcWithInitialValues(const GrFragmentStage*, int stageCount, GrColor startColor,
                                GrColorComponentFlags flags, bool areCoverageStages,
                                const GrGeometryProcessor* gp = NULL);
 
     bool isSolidWhite() const { return fInOut.isSolidWhite(); }
     bool isOpaque() const { return fInOut.isOpaque(); }
+    bool isSingleComponent() const { return fInOut.isSingleComponent(); }
 
     GrColor color() const { return fInOut.color(); }
     uint8_t validFlags() const { return fInOut.validFlags(); }
 
     /**
      * Returns the index of the first effective color stage. If an intermediate stage doesn't read
      * its input or has a known output, then we can ignore all earlier stages since they will not
      * affect the final output. Thus the first effective stage index is the index to the first stage
      * that will have an effect on the final output.
      *
@@ skipping 28 matching lines @@
 private:
     GrInvariantOutput fInOut;
     int fFirstEffectStageIndex;
     bool fInputColorIsUsed;
     GrColor fInputColor;
     bool fRemoveVertexAttrib;
     bool fReadsDst;
 };
 
 #endif