[WIP] Port media metrics to TBMv2

telemetry/telemetry/internal/actions/play.js

Index: telemetry/telemetry/internal/actions/play.js
diff --git a/telemetry/telemetry/internal/actions/play.js b/telemetry/telemetry/internal/actions/play.js
index c646d78ad7a0e7b31c26d676eae33e36cd7941ec..f47936bd2ce2a96dd0a1564659d87bdbc866b611 100644
--- a/telemetry/telemetry/internal/actions/play.js
+++ b/telemetry/telemetry/internal/actions/play.js
@@ -24,6 +24,9 @@
     window.__registerHTML5ErrorEvents(element);
     window.__registerHTML5EventCompleted(element, 'playing');
     window.__registerHTML5EventCompleted(element, 'ended');
+    element.addEventListener('durationchange', function(e) {
+      performance.mark('duration-' + element.duration);
+    });
 
     var willPlayEvent = document.createEvent('Event');
     willPlayEvent.initEvent('willPlay', false, false);