Add SK_SUPPORT_LEGACY_PORTER_DUFF macro.

src/effects/SkPorterDuff.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkPorterDuff.h"
 #include "SkXfermode.h"
 
+#ifdef SK_SUPPORT_LEGACY_PORTER_DUFF
+
 /*  This file just exists as a compatibility layer, gluing the PorterDuff API
     into the (extended) SkXfermode API
  */
 
 #define MAKE_PAIR(mode) { SkPorterDuff::k##mode##_Mode, SkXfermode::k##mode##_Mode }
 
 // this table must be in SkPorterDuff::Mode order, so it can be indexed directly
 // with a porterduff mode.
 static const struct Pair {
     SkPorterDuff::Mode  fPD;
@@ skipping 55 matching lines @@
     return find_pdmode(xfmode, pdmode);
 }
 
 SkXfermodeProc SkPorterDuff::GetXfermodeProc(Mode mode) {
     return SkXfermode::GetProc(gPairs[mode].fXF);
 }
 
 SkXfermodeProc16 SkPorterDuff::GetXfermodeProc16(Mode mode, SkColor srcColor) {
     return SkXfermode::GetProc16(gPairs[mode].fXF, srcColor);
 }
+
+#endif