Add Element::subResourceAttributeName() virtual function

Source/core/html/HTMLTableCellElement.cpp

Index: Source/core/html/HTMLTableCellElement.cpp
diff --git a/Source/core/html/HTMLTableCellElement.cpp b/Source/core/html/HTMLTableCellElement.cpp
index 489965c443bb7d9d2d619b2f7a3f6d91e3da8a7b..a68ba17e2da86328e75741cb5603a1f065ab38ef 100644
--- a/Source/core/html/HTMLTableCellElement.cpp
+++ b/Source/core/html/HTMLTableCellElement.cpp
@@ -133,6 +133,11 @@ bool HTMLTableCellElement::hasLegalLinkAttribute(const QualifiedName& name) cons
     return (hasLocalName(tdTag) && name == backgroundAttr) || HTMLTablePartElement::hasLegalLinkAttribute(name);
 }
 
+const QualifiedName& HTMLTableCellElement::subResourceAttributeName() const
+{
+    return hasLocalName(tdTag) ? backgroundAttr : HTMLTablePartElement::subResourceAttributeName();
+}
+
 const AtomicString& HTMLTableCellElement::abbr() const
 {
     return fastGetAttribute(abbrAttr);