| Index: Source/core/html/HTMLIFrameElement.h | 
| diff --git a/Source/core/html/HTMLIFrameElement.h b/Source/core/html/HTMLIFrameElement.h | 
| index 3694a9fff4993b1856d8da6ed2eda266df1d7c9d..2e99bbfebac2c36d6398bcf99a57769bdf51db8a 100644 | 
| --- a/Source/core/html/HTMLIFrameElement.h | 
| +++ b/Source/core/html/HTMLIFrameElement.h | 
| @@ -31,6 +31,7 @@ namespace blink { | 
|  | 
| class HTMLIFrameElement final : public HTMLFrameElementBase, public DOMSettableTokenListObserver { | 
| DEFINE_WRAPPERTYPEINFO(); | 
| +    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN_NESTED(HTMLIFrameElement, HTMLFrameElementBase); | 
| public: | 
| DECLARE_NODE_FACTORY(HTMLIFrameElement); | 
| DECLARE_VIRTUAL_TRACE(); | 
|  |