Don't create a GXPFactory when blend is SrcOver

src/gpu/GrPaint.cpp

 
 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrPaint.h"
 
@@ skipping 32 matching lines @@
                                                                      matrix, params))->unref();
 }
 
 bool GrPaint::isConstantBlendedColor(GrColor* color) const {
     GrProcOptInfo colorProcInfo;
     colorProcInfo.calcWithInitialValues(fColorFragmentProcessors.begin(),
                                         this->numColorFragmentProcessors(), fColor,
                                         kRGBA_GrColorComponentFlags, false);
 
     GrXPFactory::InvariantBlendedColor blendedColor;
-    fXPFactory->getInvariantBlendedColor(colorProcInfo, &blendedColor);
+    if (fXPFactory) {
+        fXPFactory->getInvariantBlendedColor(colorProcInfo, &blendedColor);
+    } else {
+        GrPorterDuffXPFactory::SrcOverInvariantBlendedColor(colorProcInfo.color(),
+                                                            colorProcInfo.validFlags(),
+                                                            colorProcInfo.isOpaque(),
+                                                            &blendedColor); 
+    }
 
     if (kRGBA_GrColorComponentFlags == blendedColor.fKnownColorFlags) {
         *color = blendedColor.fKnownColor;
         return true;
     }
     return false;
 }