Use static XPF for porter duff xp factories.

src/gpu/SkGr.cpp

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGr.h"
 
 #include "GrDrawTargetCaps.h"
@@ skipping 457 matching lines @@
     SkXfermode::Coeff dm;
 
     SkXfermode* mode = skPaint.getXfermode();
     GrFragmentProcessor* fragmentProcessor = NULL;
     GrXPFactory* xpFactory = NULL;
     if (SkXfermode::AsFragmentProcessorOrXPFactory(mode, &fragmentProcessor, &xpFactory,
                                                    &sm, &dm)) {
         if (fragmentProcessor) {
             SkASSERT(NULL == xpFactory);
             grPaint->addColorProcessor(fragmentProcessor)->unref();
-            xpFactory = GrPorterDuffXPFactory::Create(SkXfermode::kOne_Coeff,
-                                                      SkXfermode::kZero_Coeff);
+            xpFactory = GrPorterDuffXPFactory::Create(SkXfermode::kSrc_Mode);
             sm = SkXfermode::kOne_Coeff;
             dm = SkXfermode::kZero_Coeff;
         }
     } else {
         // Fall back to src-over
-        xpFactory = GrPorterDuffXPFactory::Create(SkXfermode::kOne_Coeff,
-                                                  SkXfermode::kISA_Coeff);
+        xpFactory = GrPorterDuffXPFactory::Create(SkXfermode::kSrcOver_Mode);
         sm = SkXfermode::kOne_Coeff;
         dm = SkXfermode::kISA_Coeff;
     }
     SkASSERT(xpFactory);
     grPaint->setXPFactory(xpFactory)->unref();
     grPaint->setBlendFunc(sk_blend_to_grblend(sm), sk_blend_to_grblend(dm));
 
     //set the color of the paint to the one of the parameter
     grPaint->setColor(paintColor);
 
@@ skipping 85 matching lines @@
         if (shader->asFragmentProcessor(context, skPaint, NULL, &paintColor, &fp) && fp) {
             grPaint->addColorProcessor(fp)->unref();
             constantColor = false;
         }
     }
 
     // The grcolor is automatically set when calling asFragmentProcessor.
     // If the shader can be seen as an effect it returns true and adds its effect to the grpaint.
     SkPaint2GrPaintNoShader(context, skPaint, paintColor, constantColor, grPaint);
 }