Measure how often Attr needs its associated Element

Source/core/dom/Attr.h

Index: Source/core/dom/Attr.h
diff --git a/Source/core/dom/Attr.h b/Source/core/dom/Attr.h
index 579a5d86465df167fa5702a4afce331e8374e0e6..4e83f0ee86b89a61a904ea3d652f3914fc1e8997 100644
--- a/Source/core/dom/Attr.h
+++ b/Source/core/dom/Attr.h
@@ -52,6 +52,12 @@ public:
     void setValue(const AtomicString&, ExceptionState&);
     void setValue(const AtomicString&);
 
+    const AtomicString& valueForBindings() const;
+    void setValueForBindings(const AtomicString&);
+
+    virtual String nodeValue() const OVERRIDE { return value(); }
+    virtual void setNodeValue(const String&) OVERRIDE;
+
     const QualifiedName& qualifiedName() const { return m_name; }
 
     void attachToElement(Element*);
@@ -70,8 +76,6 @@ private:
     virtual String nodeName() const OVERRIDE { return name(); }
     virtual NodeType nodeType() const OVERRIDE { return ATTRIBUTE_NODE; }
 
-    virtual String nodeValue() const OVERRIDE { return value(); }
-    virtual void setNodeValue(const String&) OVERRIDE;
     virtual PassRefPtr<Node> cloneNode(bool deep = true) OVERRIDE;
 
     virtual bool isAttributeNode() const OVERRIDE { return true; }
@@ -82,7 +86,7 @@ private:
     Attribute& elementAttribute();
 
     // Attr wraps either an element/name, or a name/value pair (when it's a standalone Node.)
-    // Note that m_name is always set, but m_element/m_standaloneValue may be null.
+    // m_name is always set. When m_element is null m_standaloneValue is not exposed to bindings.
     Element* m_element;
     QualifiedName m_name;
     AtomicString m_standaloneValue;