Convert wallpaper picker to v2 app

chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_images_grid.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.
 
 cr.define('wallpapers', function() {
   /** @const */ var ArrayDataModel = cr.ui.ArrayDataModel;
   /** @const */ var Grid = cr.ui.Grid;
   /** @const */ var GridItem = cr.ui.GridItem;
   /** @const */ var GridSelectionController = cr.ui.GridSelectionController;
   /** @const */ var ListSingleSelectionModel = cr.ui.ListSingleSelectionModel;
@@ skipping 14 matching lines @@
     return el;
   }
 
   WallpaperThumbnailsGridItem.prototype = {
     __proto__: GridItem.prototype,
 
     /** @override */
     decorate: function() {
       GridItem.prototype.decorate.call(this);
       var imageEl = cr.doc.createElement('img');
-      // Thumbnail
-      imageEl.src = this.dataItem.baseURL + ThumbnailSuffix;
-      // Remove any garbage added by GridItem and ListItem decorators.
-      this.textContent = '';
-      this.appendChild(imageEl);
+      var xhr = new XMLHttpRequest();
+      xhr.open('GET', this.dataItem.baseURL + ThumbnailSuffix, true);
+      xhr.responseType = 'blob';
+      xhr.send(null);
+      var self = this;
+      xhr.addEventListener('load', function(e) {
+        if (xhr.status === 200) {
+          self.textContent = '';
+          imageEl.src = window.URL.createObjectURL(xhr.response);
+          imageEl.addEventListener('load', function(e) {
+            window.URL.revokeObjectURL(this.src);
+          });
+          self.appendChild(imageEl);
+        }
+      });
     },
   };
 
   /**
    * Creates a selection controller that wraps selection on grid ends
    * and translates Enter presses into 'activate' events.
    * @param {cr.ui.ListSelectionModel} selectionModel The selection model to
    *     interact with.
    * @param {cr.ui.Grid} grid The grid to interact with.
    * @constructor
@@ skipping 98 matching lines @@
       this.columns = 0;
       this.redraw();
       this.focus();
     }
   };
 
   return {
     WallpaperThumbnailsGrid: WallpaperThumbnailsGrid
   };
 });