Introduce DEFINE_RENDER_OBJECT_TYPE_CASTS to replace manual toRenderFoo, and use it

Source/core/rendering/RenderGrid.h

Index: Source/core/rendering/RenderGrid.h
diff --git a/Source/core/rendering/RenderGrid.h b/Source/core/rendering/RenderGrid.h
index 9071e6a208b2182325e6ce2e3106a9e52f9dd493..d1f4adf3ff12e5026ba3ac856605deb571e839d1 100644
--- a/Source/core/rendering/RenderGrid.h
+++ b/Source/core/rendering/RenderGrid.h
@@ -157,20 +157,7 @@ private:
     bool m_gridItemOverflowGridArea;
 };
 
-inline RenderGrid* toRenderGrid(RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderGrid());
-    return static_cast<RenderGrid*>(object);
-}
-
-inline const RenderGrid* toRenderGrid(const RenderObject* object)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderGrid());
-    return static_cast<const RenderGrid*>(object);
-}
-
-// Catch unneeded cast.
-void toRenderGrid(const RenderGrid*);
+DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderGrid, isRenderGrid());
 
 } // namespace WebCore