Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/svg/RenderSVGContainer.h

Index: Source/core/rendering/svg/RenderSVGContainer.h
diff --git a/Source/core/rendering/svg/RenderSVGContainer.h b/Source/core/rendering/svg/RenderSVGContainer.h
index b25932bedefacdf30b68445ef4f62e21e07667cd..fd4e74db96be8735290c96cd219817e30bd5cc40 100644
--- a/Source/core/rendering/svg/RenderSVGContainer.h
+++ b/Source/core/rendering/svg/RenderSVGContainer.h
@@ -87,20 +87,7 @@ private:
     bool m_needsBoundariesUpdate : 1;
 };
 
-inline RenderSVGContainer* toRenderSVGContainer(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isSVGContainer());
-    return static_cast<RenderSVGContainer*>(object);
-}
-
-inline const RenderSVGContainer* toRenderSVGContainer(const RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isSVGContainer());
-    return static_cast<const RenderSVGContainer*>(object);
-}
-
-// This will catch anyone doing an unnecessary cast.
-void toRenderSVGContainer(const RenderSVGContainer*);
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderSVGContainer, isSVGContainer());
 
 } // namespace WebCore