Changing response value in web ui callback to use PrinterSetupResult

Change-Id: I92425dc2d51b4b2397651e31fe55aaa604265ab9
Reviewed-on: https://chromium-review.googlesource.com/1110842Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
Commit-Queue: David Valleau <valleau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569661}

chrome/browser/ui/webui/settings/chromeos/cups_printers_handler.cc

@@ -334,7 +334,8 @@ void CupsPrintersHandler::HandleUpdateCupsPrinter(const base::ListValue* args) {
 
   // TODO(xdai): Replace "on-add-cups-printer" callback with Promise resolve
   // function.
-  FireWebUIListener("on-add-cups-printer", base::Value(true),
+  FireWebUIListener("on-add-cups-printer",
+                    base::Value(PrinterSetupResult::kSuccess),
                     base::Value(printer_name));
 }