Convert track-webvtt-tc[019-021] tests to testharness.js

third_party/WebKit/LayoutTests/media/track/track-helpers.js

Index: third_party/WebKit/LayoutTests/media/track/track-helpers.js
diff --git a/third_party/WebKit/LayoutTests/media/track/track-helpers.js b/third_party/WebKit/LayoutTests/media/track/track-helpers.js
index 0e5db69461f06b2ae6e8442795cb30ee5599718f..26a0698d234d6095c91d7bc745f74f152428a62f 100644
--- a/third_party/WebKit/LayoutTests/media/track/track-helpers.js
+++ b/third_party/WebKit/LayoutTests/media/track/track-helpers.js
@@ -24,4 +24,18 @@ function assert_cues_match(cues, expected, properties) {
         for (var property of properties)

[foolip, 2016/06/02 09:14:18]

Is the properties array really needed? Can't this use
Object.getOwnPropertyNames(expected) instead? At the call sites it looks a bit
redundant.

[fs, 2016/06/02 09:32:46]

Yes, that ought to work (with s/expected/expectedItem/ presumably.)

[Srirama, 2016/06/02 09:59:27]

Done.

             assert_equals(cue[property], expectedItem[property]);
     }
+}
+
+function check_cues_from_track(src, func) {
+    async_test(function(t) {
+        var video = document.createElement("video");
+        var trackElement = document.createElement("track");
+        trackElement.src = src;
+        trackElement.default = true;
+        video.appendChild(trackElement);
+
+        trackElement.onload = t.step_func_done(function() {
+            func(trackElement.track);
+        });
+    }, "Check cues from " + src);
 }