Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/svg/RenderSVGImage.h

Index: Source/core/rendering/svg/RenderSVGImage.h
diff --git a/Source/core/rendering/svg/RenderSVGImage.h b/Source/core/rendering/svg/RenderSVGImage.h
index 15c5b5c9391d53f458bb760b2af779df891bdac2..ce1536de66454f8ad945d8d30ef3d931390df847 100644
--- a/Source/core/rendering/svg/RenderSVGImage.h
+++ b/Source/core/rendering/svg/RenderSVGImage.h
@@ -81,20 +81,7 @@ private:
     OwnPtr<ImageBuffer> m_bufferedForeground;
 };
 
-inline RenderSVGImage* toRenderSVGImage(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isSVGImage());
-    return static_cast<RenderSVGImage*>(object);
-}
-
-inline const RenderSVGImage* toRenderSVGImage(const RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isSVGImage());
-    return static_cast<const RenderSVGImage*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toRenderSVGImage(const RenderSVGImage*);
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderSVGImage, isSVGImage());
 
 } // namespace WebCore