Use reference for FillLayer if possible

Source/core/css/resolver/AnimatedStyleBuilder.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 126 matching lines @@
 
 PassRefPtr<SVGLength> animatableValueToNonNegativeSVGLength(const AnimatableValue* value)
 {
     RefPtr<SVGLength> length = toAnimatableSVGLength(value)->toSVGLength();
     if (length->valueInSpecifiedUnits() < 0)
         length->setValueInSpecifiedUnits(0);
     return length.release();
 }
 
 template <CSSPropertyID property>
-void setOnFillLayers(FillLayer* fillLayer, const AnimatableValue* value, StyleResolverState& state)
+void setOnFillLayers(FillLayer& fillLayers, const AnimatableValue* value, StyleResolverState& state)
 {
     const WillBeHeapVector<RefPtrWillBeMember<AnimatableValue> >& values = toAnimatableRepeatable(value)->values();
     ASSERT(!values.isEmpty());
+    FillLayer* fillLayer = &fillLayers;
     FillLayer* prev = 0;
     for (size_t i = 0; i < values.size(); ++i) {
         if (!fillLayer) {
             switch (property) {
             case CSSPropertyBackgroundImage:
             case CSSPropertyBackgroundPositionX:
             case CSSPropertyBackgroundPositionY:
             case CSSPropertyBackgroundSize:
             case CSSPropertyWebkitBackgroundSize:
                 fillLayer = new FillLayer(BackgroundFillLayer);
@@ skipping 469 matching lines @@
         return;
     case CSSPropertyZoom:
         style->setZoom(clampTo<float>(toAnimatableDouble(value)->toDouble(), std::numeric_limits<float>::denorm_min()));
         return;
     default:
         ASSERT_NOT_REACHED();
     }
 }
 
 } // namespace WebCore