diff --git a/mozilla/layout/xml/content/src/nsXMLDocumentType.cpp b/mozilla/layout/xml/content/src/nsXMLDocumentType.cpp
index deb0319075c..cd55d339b4d 100644
--- a/mozilla/layout/xml/content/src/nsXMLDocumentType.cpp
+++ b/mozilla/layout/xml/content/src/nsXMLDocumentType.cpp
@@ -336,6 +336,12 @@ nsXMLDocumentType::List(FILE* out, PRInt32 aIndent) const
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsXMLDocumentType::DumpContent(FILE* out, PRInt32 aIndent,PRBool aDumpAll) const
+{
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsXMLDocumentType::HandleDOMEvent(nsIPresContext* aPresContext,
                                            nsEvent* aEvent,