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

third_party/WebKit/LayoutTests/media/track/track-webvtt-tc000-empty.html

Index: third_party/WebKit/LayoutTests/media/track/track-webvtt-tc000-empty.html
diff --git a/third_party/WebKit/LayoutTests/media/track/track-webvtt-tc000-empty.html b/third_party/WebKit/LayoutTests/media/track/track-webvtt-tc000-empty.html
index 6342c31cddc42814b7afa32cf04e78dffe7ae53b..b41ee48640da5a913766bcfe859cff076e5f0ca6 100644
--- a/third_party/WebKit/LayoutTests/media/track/track-webvtt-tc000-empty.html
+++ b/third_party/WebKit/LayoutTests/media/track/track-webvtt-tc000-empty.html
@@ -4,14 +4,16 @@
         <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 
         <script src=../media-file.js></script>
+        <!-- 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>            
- 
+        <script>
+
             function trackLoaded()
             {
                 findMediaElement();
                 testExpected("video.textTracks[0].cues.length", "0");
-                
+
                 endTest();
             }