Re-land "Improve support for :read-only and :read-write pseudoclasses".

Source/core/html/HTMLElement.h

Index: Source/core/html/HTMLElement.h
diff --git a/Source/core/html/HTMLElement.h b/Source/core/html/HTMLElement.h
index 6d467dfc3ad815570053ce574685f81939b72584..e28af443e3efd13117b0d6739e0c217b55f16fc6 100644
--- a/Source/core/html/HTMLElement.h
+++ b/Source/core/html/HTMLElement.h
@@ -88,6 +88,9 @@ public:
 
     static const AtomicString& eventNameForAttributeName(const QualifiedName& attrName);
 
+    virtual bool matchesReadOnlyPseudoClass() const OVERRIDE;
+    virtual bool matchesReadWritePseudoClass() const OVERRIDE;
+
 protected:
     HTMLElement(const QualifiedName& tagName, Document&, ConstructionType);