--- a/content/media/TextTrackList.cpp
+++ b/content/media/TextTrackList.cpp
@@ -30,16 +30,20 @@ TextTrackList::TextTrackList(nsPIDOMWind
 
 TextTrackList::TextTrackList(nsPIDOMWindow* aOwnerWindow,
                              TextTrackManager* aTextTrackManager)
  : DOMEventTargetHelper(aOwnerWindow)
  , mTextTrackManager(aTextTrackManager)
 {
 }
 
+TextTrackList::~TextTrackList()
+{
+}
+
 void
 TextTrackList::UpdateAndGetShowingCues(nsTArray<nsRefPtr<TextTrackCue> >& aCues)
 {
   nsTArray< nsRefPtr<TextTrackCue> > cues;
   for (uint32_t i = 0; i < Length(); i++) {
     TextTrackMode mode = mTextTracks[i]->Mode();
     // If the mode is hidden then we just need to update the active cue list,
     // we don't need to show it on the video.

--- a/content/media/TextTrackList.h
+++ b/content/media/TextTrackList.h
@@ -23,16 +23,17 @@ class TrackEventRunner;
 class TextTrackList MOZ_FINAL : public DOMEventTargetHelper
 {
 public:
   NS_DECL_ISUPPORTS_INHERITED
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(TextTrackList, DOMEventTargetHelper)
 
   TextTrackList(nsPIDOMWindow* aOwnerWindow);
   TextTrackList(nsPIDOMWindow* aOwnerWindow, TextTrackManager* aTextTrackManager);
+  ~TextTrackList();
 
   virtual JSObject* WrapObject(JSContext* aCx) MOZ_OVERRIDE;
 
   uint32_t Length() const
   {
     return mTextTracks.Length();
   }