Fix img misalign and hide "by" when nothing selected in new wallpaepr picker ui

chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_manager.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.
 
 /**
  * WallpaperManager constructor.
  *
  * WallpaperManager objects encapsulate the functionality of the wallpaper
  * manager extension.
  *
@@ skipping 192 matching lines @@
    * @param {{baseURL: string, dynamicURL: string, layout: string,
    *          author: string, authorWebsite: string}}
    *     selectedItem selected wallpaper item in grid.
    * @private
    */
   WallpaperManager.prototype.setWallpaperAttribution_ = function(selectedItem) {
     if (selectedItem) {
       $('author-name').textContent = selectedItem.author;
       $('author-website').textContent = $('author-website').href =
           selectedItem.authorWebsite;
+      $('wallpaper-attribute').hidden = false;
       return;
     }
+    $('wallpaper-attribute').hidden = true;
     $('author-name').textContent = '';
     $('author-website').textContent = $('author-website').href = '';
   };
 
   /**
    * Resize thumbnails grid and categories list to fit the new window size.
    */
   WallpaperManager.prototype.onResize_ = function() {
     this.wallpaperGrid_.redraw();
     this.categoriesList_.redraw();
@@ skipping 129 matching lines @@
             authorWebsite: this.manifest_.wallpaper_list[key].author_website
           };
           wallpapersDataModel.push(wallpaperInfo);
         }
       }
       this.wallpaperGrid_.dataModel = wallpapersDataModel;
     }
   };
 
 })();