Remove compiler feature detection for = delete

sky/engine/core/dom/DocumentFragment.h

Index: sky/engine/core/dom/DocumentFragment.h
diff --git a/sky/engine/core/dom/DocumentFragment.h b/sky/engine/core/dom/DocumentFragment.h
index 1ca87bbef4384359db5081fd30d84df120768c89..31408beee75ab3d6447f39dff90dbb709c93a648 100644
--- a/sky/engine/core/dom/DocumentFragment.h
+++ b/sky/engine/core/dom/DocumentFragment.h
@@ -45,7 +45,7 @@ private:
     virtual PassRefPtrWillBeRawPtr<Node> cloneNode(bool deep = true) override;
     virtual bool childTypeAllowed(NodeType) const override;
 
-    bool isDocumentFragment() const WTF_DELETED_FUNCTION; // This will catch anyone doing an unnecessary check.
+    bool isDocumentFragment() const = delete; // This will catch anyone doing an unnecessary check.
 };
 
 DEFINE_NODE_TYPE_CASTS(DocumentFragment, isDocumentFragment());