Add TODOs to convert from video-test.js to testharness.js

third_party/WebKit/LayoutTests/media/video-error-does-not-exist.html

 <p>Test that the media element is in correct state after load fails.</p>
 <video controls></video>
+<!-- TODO(philipj): Convert test to testharness.js. crbug.com/588956
+     (Please avoid writing new tests using video-test.js) -->
 <script src=video-test.js></script>
 <script>
 
     consoleWrite("");
     testExpected("video.error", null);
 
     waitForEventAndTest("canplaythrough", "false");
-    
+
     waitForEvent("error", function () {
         testExpected("video.error", null, "!=");
         testExpected("video.error.code", MediaError.MEDIA_ERR_SRC_NOT_SUPPORTED);
-    
+
         testExpected("video.networkState", HTMLMediaElement.NETWORK_NO_SOURCE);
-    
+
         testExpected("isNaN(video.duration)", true);
         testExpected("video.currentTime", 0);
         testExpected("video.buffered.length", 0);
         testExpected("video.seekable.length", 0);
         testExpected("video.buffered.length", 0);
         endTest();
     });
-    
+
     video.src = "content/does-not-exist.mpeg";
     consoleWrite("");
 </script>