Fix leak with nsCOMPtr. r=brendan, a=brendan

widget/src/windows/nsMenu.cpp

@@ -733,8 +733,8 @@ void nsMenu::LoadMenuItem(
       return; //NS_ERROR_FAILURE;
     }
   
-    nsIDOMElement * keyElement = nsnull;
+    nsCOMPtr<nsIDOMElement> keyElement;
-    xulDocument->GetElementById(keyValue, &keyElement);
+    xulDocument->GetElementById(keyValue, getter_AddRefs(keyElement));
     
     if(keyElement){
         PRUint8 modifiers = knsMenuItemNoModifier;