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

third_party/WebKit/LayoutTests/media/track/text-track-is-reachable.html

Index: third_party/WebKit/LayoutTests/media/track/text-track-is-reachable.html
diff --git a/third_party/WebKit/LayoutTests/media/track/text-track-is-reachable.html b/third_party/WebKit/LayoutTests/media/track/text-track-is-reachable.html
index bba1fb908d67c4d92c63b2dc1a246aca6dedcf37..059d48b8ac8b5f518b38df57ead71787e91ce54e 100644
--- a/third_party/WebKit/LayoutTests/media/track/text-track-is-reachable.html
+++ b/third_party/WebKit/LayoutTests/media/track/text-track-is-reachable.html
@@ -4,6 +4,8 @@
         <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>
 
@@ -11,7 +13,7 @@
             {
                 if (window.GCController)
                     return GCController.collectAll();
-            
+
                 // Force garbage collection
                 for (var ndx = 0; ndx < 99000; ndx++)
                     var str = new String("1234");