Using random wallpaper until user select one

chrome/browser/resources/chromeos/user_images_grid.js

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
 cr.define('options', function() {
   const ArrayDataModel = cr.ui.ArrayDataModel;
   const Grid = cr.ui.Grid;
   const GridItem = cr.ui.GridItem;
   const GridSelectionController = cr.ui.GridSelectionController;
   const ListSingleSelectionModel = cr.ui.ListSingleSelectionModel;
 
@@ skipping 108 matching lines @@
     /**
      * URL of the image selected.
      * @type {string?}
      */
     get selectedItemUrl() {
       var selectedItem = this.selectedItem;
       return selectedItem ? selectedItem.url : null;
     },
     set selectedItemUrl(url) {
       for (var i = 0, el; el = this.dataModel.item(i); i++) {
-        if (el.url === url) {
-          this.inProgramSelection_ = true;
-          this.selectionModel.selectedIndex = i;
-          this.selectionModel.leadIndex = i;
-          this.inProgramSelection_ = false;
-        }
+        if (el.url === url)
+          this.selectedItemIndex = i;
       }
     },
 
+    /**
+     * Set index to the image selected.
+     * @type {number} index The index of selected image.
+     */
+    set selectedItemIndex(index) {
+      this.inProgramSelection_ = true;
+      this.selectionModel.selectedIndex = index;
+      this.inProgramSelection_ = false;
+    },
+
     /** @inheritDoc */
     get selectedItem() {
       var index = this.selectionModel.selectedIndex;
       return index != -1 ? this.dataModel.item(index) : null;
     },
     set selectedItem(selectedItem) {
       var index = this.indexOf(selectedItem);
       this.inProgramSelection_ = true;
       this.selectionModel.selectedIndex = index;
       this.selectionModel.leadIndex = index;
@@ skipping 93 matching lines @@
   UserImagesGrid.ButtonImages = {
     TAKE_PHOTO: 'chrome://theme/IDR_BUTTON_USER_IMAGE_TAKE_PHOTO',
     CHOOSE_FILE: 'chrome://theme/IDR_BUTTON_USER_IMAGE_CHOOSE_FILE',
     PROFILE_PICTURE: 'chrome://theme/IDR_PROFILE_PICTURE_LOADING'
   };
 
   return {
     UserImagesGrid: UserImagesGrid
   };
 });