Give nsTextControlFrame a notification when readonly on a TextArea is changed.

content/html/content/src/nsHTMLTextAreaElement.cpp

@@ -478,6 +478,10 @@ nsHTMLTextAreaElement::GetStyleHintForAttributeChange(
     const nsIAtom* aAttribute,
     PRInt32 *aHint) const
 {
-  nsGenericHTMLElement::GetStyleHintForCommonAttributes(this, aAttribute, aHint);
+  if (nsHTMLAtoms::readonly == aAttribute) {
+    *aHint = NS_STYLE_HINT_CONTENT;
+  } else {
+    nsGenericHTMLElement::GetStyleHintForCommonAttributes(this, aAttribute, aHint);
+  }
   return NS_OK;
 }

layout/html/content/src/nsHTMLTextAreaElement.cpp

@@ -478,6 +478,10 @@ nsHTMLTextAreaElement::GetStyleHintForAttributeChange(
     const nsIAtom* aAttribute,
     PRInt32 *aHint) const
 {
-  nsGenericHTMLElement::GetStyleHintForCommonAttributes(this, aAttribute, aHint);
+  if (nsHTMLAtoms::readonly == aAttribute) {
+    *aHint = NS_STYLE_HINT_CONTENT;
+  } else {
+    nsGenericHTMLElement::GetStyleHintForCommonAttributes(this, aAttribute, aHint);
+  }
   return NS_OK;
 }