r-input> and <paper-textarea>.
            // In particular, it resets them to what it thinks the default value
            // is (i.e. "", before the bindings have ran), and since this is
            // a programmatic update, it also doesn't fire any events.
            // Which means we need to manually update the native element's value.
            if (el.inputElement) {
              el.inputElement.value = el.value;
            } else if (el.textarea) {
              el.textarea.value = el.value;
     