Delay string conversion of attribute names until needed.

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 2770150fd8e6e417c6bdb39cafd9fa3ce5128829..5c65b6217e409c5fa94a980004b31ea7e5839ea2 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -2941,21 +2941,21 @@ void Element::willModifyAttribute(const QualifiedName& name, const AtomicString&
 void Element::didAddAttribute(const QualifiedName& name, const AtomicString& value)
 {
     attributeChanged(name, value);
-    InspectorInstrumentation::didModifyDOMAttr(this, name.toString(), value);
+    InspectorInstrumentation::didModifyDOMAttr(this, name, value);
     dispatchSubtreeModifiedEvent();
 }
 
 void Element::didModifyAttribute(const QualifiedName& name, const AtomicString& value)
 {
     attributeChanged(name, value);
-    InspectorInstrumentation::didModifyDOMAttr(this, name.toString(), value);
+    InspectorInstrumentation::didModifyDOMAttr(this, name, value);
     // Do not dispatch a DOMSubtreeModified event here; see bug 81141.
 }
 
 void Element::didRemoveAttribute(const QualifiedName& name)
 {
     attributeChanged(name, nullAtom);
-    InspectorInstrumentation::didRemoveDOMAttr(this, name.toString());
+    InspectorInstrumentation::didRemoveDOMAttr(this, name);
     dispatchSubtreeModifiedEvent();
 }