Use reference for FillLayer if possible

Source/core/rendering/RenderBox.h

Index: Source/core/rendering/RenderBox.h
diff --git a/Source/core/rendering/RenderBox.h b/Source/core/rendering/RenderBox.h
index ec4682cbce8439c73d811e872f3c5adc10dbff1b..4f853534d5dcf88eea53b952033a4f914c9cb1e9 100644
--- a/Source/core/rendering/RenderBox.h
+++ b/Source/core/rendering/RenderBox.h
@@ -634,8 +634,8 @@ protected:
 
     void paintBackground(const PaintInfo&, const LayoutRect&, BackgroundBleedAvoidance = BackgroundBleedNone);
 
-    void paintFillLayer(const PaintInfo&, const Color&, const FillLayer*, const LayoutRect&, BackgroundBleedAvoidance, CompositeOperator, RenderObject* backgroundObject);
-    void paintFillLayers(const PaintInfo&, const Color&, const FillLayer*, const LayoutRect&, BackgroundBleedAvoidance = BackgroundBleedNone, CompositeOperator = CompositeSourceOver, RenderObject* backgroundObject = 0);
+    void paintFillLayer(const PaintInfo&, const Color&, const FillLayer&, const LayoutRect&, BackgroundBleedAvoidance, CompositeOperator, RenderObject* backgroundObject);
+    void paintFillLayers(const PaintInfo&, const Color&, const FillLayer&, const LayoutRect&, BackgroundBleedAvoidance = BackgroundBleedNone, CompositeOperator = CompositeSourceOver, RenderObject* backgroundObject = 0);
 
     void paintMaskImages(const PaintInfo&, const LayoutRect&);
     void paintBoxDecorationBackgroundWithRect(PaintInfo&, const LayoutPoint&, const LayoutRect&);
@@ -675,7 +675,7 @@ private:
     void shrinkToFitWidth(const LayoutUnit availableSpace, const LayoutUnit logicalLeftValue, const LayoutUnit bordersPlusPadding, LogicalExtentComputedValues&) const;
 
     // Returns true if we did a full repaint
-    bool repaintLayerRectsForImage(WrappedImagePtr image, const FillLayer* layers, bool drawingBackground);
+    bool repaintLayerRectsForImage(WrappedImagePtr, const FillLayer&, bool drawingBackground);
 
     bool skipContainingBlockForPercentHeightCalculation(const RenderBox* containingBlock) const;