[CUPS] Only allow set up a printer if manufacturer & model or the PPD file is specified.

chrome/browser/resources/settings/printing_page/cups_add_printer_dialog.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview 'settings-cups-add-printer-dialog' includes multiple dialogs to
  * set up a new CUPS printer.
  * Subdialogs include:
  * - 'add-printer-discovery-dialog' is a dialog showing discovered printers on
  *   the network that are available for setup.
@@ skipping 269 matching lines @@
   },
 
   /**
    * @param {string} path The full path of the file
    * @return {string} The base name of the file
    * @private
    */
   getBaseName_: function(path) {
     return path.substring(path.lastIndexOf('/') + 1);
   },
+
+  /**
+   * @param {string} printerManufacturer
+   * @param {string} printerModel
+   * @param {string} printerPPDPath
+   * @return {boolean} Whether we have enough information to set up the printer
+   * @private
+   */
+   canAddPrinter_: function(printerManufacturer, printerModel, printerPPDPath) {
+     if ((printerManufacturer && printerModel) || printerPPDPath)

[michaelpg, 2017/05/08 23:46:57]

nit: just return ((pM && pM) || pP) directly instead of the if

[xdai1, 2017/05/09 00:34:23]

Done.

+       return true;
+     return false;
+   },
 });
 
 Polymer({
   is: 'add-printer-configuring-dialog',
 
   properties: {
     printerName: String,
     dialogTitle: String,
   },
 
@@ skipping 198 matching lines @@
   onAddPrinter_: function(success, printerName) {
     this.$$('add-printer-configuring-dialog').close();
     if (success)
       return;
 
     if (this.previousDialog_ == AddPrinterDialogs.MANUFACTURER) {
       this.setupFailed = true;
     }
   },
 });