[S.P.] Use LayoutObject references in SVGFilterPainter.

Source/core/paint/SVGFilterPainter.h

Index: Source/core/paint/SVGFilterPainter.h
diff --git a/Source/core/paint/SVGFilterPainter.h b/Source/core/paint/SVGFilterPainter.h
index 0e7dc0d02d55b661bcc0ce5582797f5ae4acbe93..1d6768d714da552014f4c87b286507cf456b9299 100644
--- a/Source/core/paint/SVGFilterPainter.h
+++ b/Source/core/paint/SVGFilterPainter.h
@@ -17,8 +17,8 @@ public:
 
     // Returns the context that should be used to paint the filter contents, or
     // null if the content should not be recorded.
-    GraphicsContext* prepareEffect(LayoutObject*, GraphicsContext*);
-    void finishEffect(LayoutObject*, GraphicsContext*);
+    GraphicsContext* prepareEffect(LayoutObject&, GraphicsContext*);
+    void finishEffect(LayoutObject&, GraphicsContext*);
 
 private:
     LayoutSVGResourceFilter& m_filter;