--- a/dom/media/MediaDecoderReader.cpp
+++ b/dom/media/MediaDecoderReader.cpp
@@ -40,17 +40,16 @@ extern LazyLogModule gMediaDecoderLog;
 MediaDecoderReader::MediaDecoderReader(MediaDecoderReaderInit& aInit)
   : mDecoder(aInit.mDecoder)
   , mTaskQueue(new TaskQueue(
       GetMediaThreadPool(MediaThreadType::PLAYBACK),
       "MediaDecoderReader::mTaskQueue",
       /* aSupportsTailDispatch = */ true))
   , mBuffered(mTaskQueue, TimeIntervals(), "MediaDecoderReader::mBuffered (Canonical)")
   , mShutdown(false)
-  , mResource(aInit.mResource)
 {
   MOZ_COUNT_CTOR(MediaDecoderReader);
   MOZ_ASSERT(NS_IsMainThread());
 }
 
 nsresult
 MediaDecoderReader::Init()
 {
@@ -62,17 +61,16 @@ MediaDecoderReader::~MediaDecoderReader(
   MOZ_ASSERT(mShutdown);
   MOZ_COUNT_DTOR(MediaDecoderReader);
 }
 
 void
 MediaDecoderReader::UpdateDuration(const media::TimeUnit& aDuration)
 {
   MOZ_ASSERT(OnTaskQueue());
-  mDuration = Some(aDuration);
   UpdateBuffered();
 }
 
 RefPtr<ShutdownPromise>
 MediaDecoderReader::Shutdown()
 {
   MOZ_ASSERT(OnTaskQueue());
   mShutdown = true;

--- a/dom/media/MediaDecoderReader.h
+++ b/dom/media/MediaDecoderReader.h
@@ -269,18 +269,16 @@ protected:
   AbstractMediaDecoder* mDecoder;
 
   // Decode task queue.
   RefPtr<TaskQueue> mTaskQueue;
 
   // Buffered range.
   Canonical<media::TimeIntervals> mBuffered;
 
-  media::NullableTimeUnit mDuration;
-
   bool mShutdown;
 
   // Used to send TimedMetadata to the listener.
   TimedMetadataEventProducer mTimedMetadataEvent;
 
   // Notify if this media is not seekable.
   MediaEventProducer<void> mOnMediaNotSeekable;
 
@@ -288,17 +286,15 @@ protected:
   MediaEventProducer<TrackInfo::TrackType> mOnTrackWaitingForKey;
 
   MediaEventProducer<nsTArray<uint8_t>, nsString> mOnEncrypted;
 
   MediaEventProducer<void> mOnWaitingForKey;
 
   MediaEventProducer<MediaResult> mOnDecodeWarning;
 
-  RefPtr<MediaResource> mResource;
-
 private:
   virtual nsresult InitInternal() = 0;
 };
 
 } // namespace mozilla
 
 #endif