Measure the impact of a propsed change to createAttribute()

Source/core/dom/Element.cpp

Index: Source/core/dom/Element.cpp
diff --git a/Source/core/dom/Element.cpp b/Source/core/dom/Element.cpp
index c2db12d8bc29a05037ba8dc3090e5c7f3f18da23..aa0585017f75b2a2ccfb58724b6b90af8a91efb8 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -2002,6 +2002,9 @@ PassRefPtrWillBeRawPtr<Attr> Element::setAttributeNode(Attr* attrNode, Exception
         return nullptr;
     }
 
+    if (!isHTMLElement() && attrNode->document().isHTMLDocument() && attrNode->name() != attrNode->name().lower())
+        UseCounter::count(document(), UseCounter::NonHTMLElementSetAttributeNodeFromHTMLDocumentNameNotLowercase);
+
     synchronizeAllAttributes();
     const UniqueElementData& elementData = ensureUniqueElementData();