Fixed the titles of the documents and the explanation of what the test does. 
diff --git a/media-source/URL-createObjectURL.html b/media-source/URL-createObjectURL.html index 9924992..e9fbed1 100644 --- a/media-source/URL-createObjectURL.html +++ b/media-source/URL-createObjectURL.html 
@@ -2,7 +2,7 @@  <html>  <head>  <meta charset='utf-8'> - <title>insertAdjacentHTML</title> + <title>URL.createObjectURL(mediaSource)</title>  <script src="/resources/testharness.js"></script>  <script src="/resources/testharnessreport.js"></script>  </head> @@ -16,8 +16,9 @@  test(function() {  var mediaSource = new MediaSource();  var url = window.URL.createObjectURL(mediaSource); - assert_not_equals(url, null); -}, "URL.createObjectURL : 2. Return a unique MediaSource object URL that can be used to dereference the mediaSource argument, and run the rest of the algorithm asynchronously."); + assert_true(url != null); + assert_true(url.match(/^blob:.+/) != null); +}, "URL.createObjectURL(mediaSource) should return a unique Blob URI.");  </script>  </body>  </html>