--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -364,22 +364,18 @@ MediaDecoderStateMachine::Initialization
   mWatchManager.Watch(mVolume, &MediaDecoderStateMachine::VolumeChanged);
   mWatchManager.Watch(mLogicalPlaybackRate, &MediaDecoderStateMachine::LogicalPlaybackRateChanged);
   mWatchManager.Watch(mPreservesPitch, &MediaDecoderStateMachine::PreservesPitchChanged);
   mWatchManager.Watch(mEstimatedDuration, &MediaDecoderStateMachine::RecomputeDuration);
   mWatchManager.Watch(mExplicitDuration, &MediaDecoderStateMachine::RecomputeDuration);
   mWatchManager.Watch(mObservedDuration, &MediaDecoderStateMachine::RecomputeDuration);
   mWatchManager.Watch(mPlayState, &MediaDecoderStateMachine::PlayStateChanged);
   mWatchManager.Watch(mLogicallySeeking, &MediaDecoderStateMachine::LogicallySeekingChanged);
-  mWatchManager.Watch(mSameOriginMedia, &MediaDecoderStateMachine::SameOriginMediaChanged);
   mWatchManager.Watch(mSentFirstFrameLoadedEvent, &MediaDecoderStateMachine::AdjustAudioThresholds);
   mWatchManager.Watch(mAudioCaptured, &MediaDecoderStateMachine::AdjustAudioThresholds);
-
-  // Propagate mSameOriginMedia to mDecodedStream.
-  SameOriginMediaChanged();
 }
 
 media::MediaSink*
 MediaDecoderStateMachine::CreateAudioSink()
 {
   RefPtr<MediaDecoderStateMachine> self = this;
   auto audioSinkCreator = [self] () {
     MOZ_ASSERT(self->OnTaskQueue());
@@ -1453,22 +1449,16 @@ void MediaDecoderStateMachine::PlayState
 }
 
 void MediaDecoderStateMachine::LogicallySeekingChanged()
 {
   MOZ_ASSERT(OnTaskQueue());
   ScheduleStateMachine();
 }
 
-void MediaDecoderStateMachine::SameOriginMediaChanged()
-{
-  MOZ_ASSERT(OnTaskQueue());
-  mStreamSink->SetSameOrigin(mSameOriginMedia);
-}
-
 void MediaDecoderStateMachine::BufferedRangeUpdated()
 {
   MOZ_ASSERT(OnTaskQueue());
 
   // While playing an unseekable stream of unknown duration, mObservedDuration
   // is updated (in AdvanceFrame()) as we play. But if data is being downloaded
   // faster than played, mObserved won't reflect the end of playable data
   // since we haven't played the frame at the end of buffered data. So update

--- a/dom/media/MediaDecoderStateMachine.h
+++ b/dom/media/MediaDecoderStateMachine.h
@@ -502,19 +502,16 @@ protected:
   void StartMediaSink();
 
   // Notification method invoked when mPlayState changes.
   void PlayStateChanged();
 
   // Notification method invoked when mLogicallySeeking changes.
   void LogicallySeekingChanged();
 
-  // Notification method invoked when mSameOriginMedia changes.
-  void SameOriginMediaChanged();
-
   // Sets internal state which causes playback of media to pause.
   // The decoder monitor must be held.
   void StopPlayback();
 
   // If the conditions are right, sets internal state which causes playback
   // of media to begin or resume.
   // Must be called with the decode monitor held.
   void MaybeStartPlayback();

--- a/dom/media/mediasink/DecodedStream.cpp
+++ b/dom/media/mediasink/DecodedStream.cpp
@@ -427,23 +427,16 @@ DecodedStream::SetPlaybackRate(double aP
 void
 DecodedStream::SetPreservesPitch(bool aPreservesPitch)
 {
   AssertOwnerThread();
   mParams.mPreservesPitch = aPreservesPitch;
 }
 
 void
-DecodedStream::SetSameOrigin(bool aSameOrigin)
-{
-  AssertOwnerThread();
-  mSameOrigin = aSameOrigin;
-}
-
-void
 DecodedStream::InitTracks()
 {
   AssertOwnerThread();
 
   if (mData->mStreamInitialized) {
     return;
   }
 

--- a/dom/media/mediasink/DecodedStream.h
+++ b/dom/media/mediasink/DecodedStream.h
@@ -56,19 +56,16 @@ public:
   void SetPreservesPitch(bool aPreservesPitch) override;
   void SetPlaying(bool aPlaying) override;
 
   void Start(int64_t aStartTime, const MediaInfo& aInfo) override;
   void Stop() override;
   bool IsStarted() const override;
   bool IsPlaying() const override;
 
-  // TODO: fix these functions that don't fit into the interface of MediaSink.
-  void SetSameOrigin(bool aSameOrigin);
-
 protected:
   virtual ~DecodedStream();
 
 private:
   void CreateData(MozPromiseHolder<GenericPromise>&& aPromise);
   void DestroyData(UniquePtr<DecodedStreamData> aData);
   void OnDataCreated(UniquePtr<DecodedStreamData> aData);
   void InitTracks();