Bug 1334112 -part3 : Trigger UpdateReadyState after unbind TrackElement's and TextTrack::SetReadyState. r=rillian

MozReview-Commit-ID: pEeOzZSpak

--HG--
extra : rebase_source : cf7759c746f3fa9221dcda03327fd6b3c5997ee7

dom/html/HTMLTrackElement.cpp

@@ -392,6 +392,7 @@ HTMLTrackElement::UnbindFromTree(bool aDeep, bool aNullParent)
     // called.
     if (mTrack) {
       mMediaParent->RemoveTextTrack(mTrack);
+      mMediaParent->UpdateReadyState();
     }
     mMediaParent = nullptr;
   }

dom/media/TextTrack.cpp

@@ -263,6 +263,7 @@ TextTrack::SetReadyState(TextTrackReadyState aState)
   if (mediaElement && (mReadyState == TextTrackReadyState::Loaded||
       mReadyState == TextTrackReadyState::FailedToLoad)) {
     mediaElement->RemoveTextTrack(this, true);
+    mediaElement->UpdateReadyState();
   }
 }