Bug 1275808 - Move the UpdateCueDisplay() into TimeMarchesOn() as step 18. r=rillian

MozReview-Commit-ID: GrcZCjstBy9

dom/html/HTMLMediaElement.cpp

@@ -4826,7 +4826,7 @@ void HTMLMediaElement::FireTimeUpdate(bool aPeriodic)
   // us before our parent. In that case UnbindFromTree will call us
   // when our parent is unlinked.
   if (mTextTrackManager) {
-    mTextTrackManager->UpdateCueDisplay();
+    mTextTrackManager->TimeMarchesOn();
   }
 }