--- a/dom/media/MediaStreamGraphImpl.h
+++ b/dom/media/MediaStreamGraphImpl.h
@@ -180,20 +180,16 @@ public:
 
   /**
    * Make this MediaStreamGraph enter forced-shutdown state. This state
    * will be noticed by the media graph thread, which will shut down all streams
    * and other state controlled by the media graph thread.
    * This is called during application shutdown.
    */
   void ForceShutDown(ShutdownTicket* aShutdownTicket);
-  /**
-   * Shutdown() this MediaStreamGraph's threads and return when they've shut down.
-   */
-  void ShutdownThreads();
 
   /**
    * Called before the thread runs.
    */
   void Init();
   // The following methods run on the graph thread (or possibly the main thread if
   // mLifecycleState > LIFECYCLE_RUNNING)
   void AssertOnGraphThreadOrNotRunning() const