Bug 1279865 - Don't run TimeMarchesOn if the MediaElement is not played. r=rillian

1. If mHasUserInteraction MediaElement is false, don't run the TimeMarchesOn because the element is not played. 2. Update the activeCueList only in TimeMarchesOn(). 3. Run TimeMarchesOn() at the beginning of play. r=rillian

MozReview-Commit-ID: BhwsIfRm3B2

dom/html/HTMLMediaElement.cpp

@@ -2599,6 +2599,7 @@ HTMLMediaElement::PlayInternal(bool aCallerIsChrome)
       break;
     case nsIDOMHTMLMediaElement::HAVE_FUTURE_DATA:
     case nsIDOMHTMLMediaElement::HAVE_ENOUGH_DATA:
+      FireTimeUpdate(false);
       DispatchAsyncEvent(NS_LITERAL_STRING("playing"));
       break;
     }