[Retry] Fix the browser crash when changing wallpaper with chrome.wallpaper API.

chrome/test/data/extensions/api_test/wallpaper/test.js

 // Copyright 2014 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.
 
 var pass = chrome.test.callbackPass;
 var fail = chrome.test.callbackFail;
 
 chrome.test.getConfig(function(config) {
 
   var baseURL = "http://a.com:" + config.testServer.port +
@@ skipping 56 matching lines @@
       }
       chrome.wallpaper.setWallpaper(
          {'url': url,
           'layout': 'CENTER_CROPPED',
           'filename': 'test'},
           // Expect a failure.
           fail(optExpectedError));
     }
   };
 
+  var testSetWallpaperThumbnail = function(relativeURL) {
+    var url = baseURL + relativeURL;
+    chrome.wallpaper.setWallpaper(
+      { 'url': url,
+        'layout': 'CENTER_CROPPED',
+        'filename': 'test',
+        'thumbnail': true
+      }, pass(function(thumbnail) {
+        var buffer = new Uint8Array(thumbnail);
+        chrome.test.assertTrue(buffer.length > 0);
+      }));
+  };
+
   chrome.test.runTests([
     function setJpgWallpaperFromAppLocalFile() {
       testSetWallpaperFromArrayBuffer('test.jpg');
     },
     function setPngWallpaperFromAppLocalFile() {
       testSetWallpaperFromArrayBuffer('test.png');
     },
     function setJpgWallpaperFromURL () {
       testSetWallpaperFromURL('test.jpg', true);
     },
@@ skipping 10 matching lines @@
     },
     function newRequestCancelPreviousRequest() {
       // The first request should be canceled. The wallpaper in the first
       // request is chosen from one of the high-resolution built-in wallpapers
       // to make sure the first setWallpaper request hasn't finished yet when
       // the second request sends out.
       testSetWallpaperFromURL('test_image_high_resolution.jpg',
                               false,
                               'Set wallpaper was canceled.');
       testSetWallpaperFromURL('test.jpg', true);
+    },
+    function getThumbnailAferSetWallpaper() {
+      testSetWallpaperThumbnail('test.jpg');
     }
   ]);
 });