fix build bustage in history

mail/components/history/history.cpp

@@ -82,4 +82,15 @@ History::UnregisterVisitedCallback(nsIURI *aURI, Link *aLink)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+History::VisitURI(nsIURI *aURI, nsIURI *aLastVisitedURI, PRUint32 aFlags)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+History::SetURITitle(nsIURI* aURI, const nsAString& aTitle)
+{
+  return NS_OK;
+}
 }