Print Preview: Merge NativeLayerStubs for tests

chrome/browser/resources/print_preview/print_preview.js

 // Copyright (c) 2012 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.
 
 // TODO(rltoscano): Move data/* into print_preview.data namespace
 
 // <include src="component.js">
 // <include src="print_preview_focus_manager.js">
 //
 
@@ skipping 37 matching lines @@
    * @extends {print_preview.Component}
    */
   function PrintPreview() {
     print_preview.Component.call(this);
 
     /**
      * Used to communicate with Chromium's print system.
      * @type {!print_preview.NativeLayer}
      * @private
      */
-    this.nativeLayer_ = new print_preview.NativeLayer();
+    this.nativeLayer_ = print_preview.NativeLayer.getInstance();
 
     /**
      * Event target that contains information about the logged in user.
      * @type {!print_preview.UserInfo}
      * @private
      */
     this.userInfo_ = new print_preview.UserInfo();
 
     /**
      * Application state.
@@ skipping 248 matching lines @@
     /**
      * Whether to show system dialog before next printing.
      * @type {boolean}
      * @private
      */
     this.showSystemDialogBeforeNextPrint_ = false;
   }
 
   PrintPreview.prototype = {
     __proto__: print_preview.Component.prototype,
+    /**
+     * @return {!print_preview.PreviewArea} The preview area. Used for tests.
+     */
+    getPreviewArea: function() {
+      return this.previewArea_;
+    },
 
     /** Sets up the page and print preview by getting the printer list. */
     initialize: function() {
       this.decorate($('print-preview'));
       if (!this.previewArea_.hasCompatiblePlugin) {
         this.setIsEnabled_(false);
       }
       this.nativeLayer_.getInitialSettings().then(
           this.onInitialSettingsSet_.bind(this));
       print_preview.PrintPreviewFocusManager.getInstance().initialize();
@@ skipping 1011 matching lines @@
 // <include src="search/destination_search.js">
 // <include src="search/provisional_destination_resolver.js">
 
 window.addEventListener('DOMContentLoaded', function() {
   var previewWindow = /** @type {{isTest: boolean}} */ (window);
   if (!previewWindow.isTest) {
     var printPreview = new print_preview.PrintPreview();
     printPreview.initialize();
   }
 });