Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/svg/RenderSVGPath.h

Index: Source/core/rendering/svg/RenderSVGPath.h
diff --git a/Source/core/rendering/svg/RenderSVGPath.h b/Source/core/rendering/svg/RenderSVGPath.h
index 5d83f86468dc24c32c738cf0a426f80cdeb9ab7a..8cec15c4c9282ac56a813018b735a8d44ebb657c 100644
--- a/Source/core/rendering/svg/RenderSVGPath.h
+++ b/Source/core/rendering/svg/RenderSVGPath.h
@@ -53,11 +53,7 @@ private:
     Vector<FloatPoint> m_zeroLengthLinecapLocations;
 };
 
-inline RenderSVGPath* toRenderSVGPath(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isSVGPath());
-    return static_cast<RenderSVGPath*>(object);
-}
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderSVGPath, isSVGPath());
 
 }