Bug 1308388. P4 - listen to 'loadeddata' to check buffer ranges. r=kaku

The buffer ranges should be known when 'loadeddata' is fired.

MozReview-Commit-ID: 4FZVJiMyucT

--HG--
extra : rebase_source : 94d06e527401abd2b9b2247cd0c447a2238943dc

dom/media/test/test_buffered.html

@@ -100,7 +100,7 @@ function startTest(test, token) {
     v.src = uri;
     v._name = test.name;
     v._test = test;
-    v.addEventListener("timeupdate", testBuffered, {once: true});
+    v.addEventListener("loadeddata", testBuffered, {once: true});
     document.body.appendChild(v);
   };