| Index: Source/core/html/HTMLSummaryElement.cpp | 
| diff --git a/Source/core/html/HTMLSummaryElement.cpp b/Source/core/html/HTMLSummaryElement.cpp | 
| index 43fa4110859d923a2f10723bda1351f2ea92fc36..d213a27e37f118e11c3e93ba3c7f04b4053a69c5 100644 | 
| --- a/Source/core/html/HTMLSummaryElement.cpp | 
| +++ b/Source/core/html/HTMLSummaryElement.cpp | 
| @@ -61,7 +61,7 @@ void HTMLSummaryElement::didAddUserAgentShadowRoot(ShadowRoot& root) | 
| HTMLDetailsElement* HTMLSummaryElement::detailsElement() const | 
| { | 
| Node* parent = NodeRenderingTraversal::parent(this); | 
| -    if (parent && parent->hasTagName(detailsTag)) | 
| +    if (isHTMLDetailsElement(parent)) | 
| return toHTMLDetailsElement(parent); | 
| return 0; | 
| } | 
|  |