--- a/dom/media/MediaDecoderStateMachine.h
+++ b/dom/media/MediaDecoderStateMachine.h
@@ -525,28 +525,16 @@ private:
 
   // FrameID which increments every time a frame is pushed to our queue.
   FrameID mCurrentFrameID;
 
   // The highest timestamp that our position has reached. Monotonically
   // increasing.
   Watchable<media::TimeUnit> mObservedDuration;
 
-  // Returns true if we're logically playing, that is, if the Play() has
-  // been called and Pause() has not or we have not yet reached the end
-  // of media. This is irrespective of the seeking state; if the owner
-  // calls Play() and then Seek(), we still count as logically playing.
-  // The decoder monitor must be held.
-  bool IsLogicallyPlaying()
-  {
-    MOZ_ASSERT(OnTaskQueue());
-    return mPlayState == MediaDecoder::PLAY_STATE_PLAYING
-           || mNextPlayState == MediaDecoder::PLAY_STATE_PLAYING;
-  }
-
   // Media Fragment end time.
   media::TimeUnit mFragmentEndTime = media::TimeUnit::Invalid();
 
   // The media sink resource.  Used on the state machine thread.
   RefPtr<media::MediaSink> mMediaSink;
 
   const RefPtr<ReaderProxy> mReader;