Make sure getAttribute() / setAttribute() callers use AtomicStrings

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 a6c5b1ee54ff2c25c92c5b9db7794592d67a2b02..01b712585fc058543991f4371b6817944777dfa2 100644
--- a/Source/core/html/HTMLTableCellElement.cpp
+++ b/Source/core/html/HTMLTableCellElement.cpp
@@ -130,12 +130,12 @@ bool HTMLTableCellElement::isURLAttribute(const Attribute& attribute) const
     return attribute.name() == backgroundAttr || HTMLTablePartElement::isURLAttribute(attribute);
 }
 
-String HTMLTableCellElement::abbr() const
+const AtomicString& HTMLTableCellElement::abbr() const
 {
     return getAttribute(abbrAttr);
 }
 
-String HTMLTableCellElement::axis() const
+const AtomicString& HTMLTableCellElement::axis() const
 {
     return getAttribute(axisAttr);
 }
@@ -145,7 +145,7 @@ void HTMLTableCellElement::setColSpan(int n)
     setIntegralAttribute(colspanAttr, n);
 }
 
-String HTMLTableCellElement::headers() const
+const AtomicString& HTMLTableCellElement::headers() const
 {
     return getAttribute(headersAttr);
 }
@@ -155,7 +155,7 @@ void HTMLTableCellElement::setRowSpan(int n)
     setIntegralAttribute(rowspanAttr, n);
 }
 
-String HTMLTableCellElement::scope() const
+const AtomicString& HTMLTableCellElement::scope() const
 {
     return getAttribute(scopeAttr);
 }