--- a/dom/media/ChannelMediaDecoder.cpp
+++ b/dom/media/ChannelMediaDecoder.cpp
@@ -482,16 +482,23 @@ ChannelMediaDecoder::ShouldThrottleDownl
   if (!stats.mDownloadRateReliable || !stats.mPlaybackRateReliable) {
     return false;
   }
   uint32_t factor =
     std::max(2u, Preferences::GetUint("media.throttle-factor", 2));
   return stats.mDownloadRate > factor * stats.mPlaybackRate;
 }
 
+already_AddRefed<nsIPrincipal>
+ChannelMediaDecoder::GetCurrentPrincipal()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  return mResource ? mResource->GetCurrentPrincipal() : nullptr;
+}
+
 bool
 ChannelMediaDecoder::IsTransportSeekable()
 {
   MOZ_ASSERT(NS_IsMainThread());
   return mResource->IsTransportSeekable();
 }
 
 void

--- a/dom/media/ChannelMediaDecoder.h
+++ b/dom/media/ChannelMediaDecoder.h
@@ -73,16 +73,17 @@ public:
 
   // Create a new decoder of the same type as this one.
   already_AddRefed<ChannelMediaDecoder> Clone(MediaDecoderInit& aInit);
 
   nsresult Load(nsIChannel* aChannel,
                 bool aIsPrivateBrowsing,
                 nsIStreamListener** aStreamListener);
 
+  already_AddRefed<nsIPrincipal> GetCurrentPrincipal() override;
   bool IsTransportSeekable() override;
   void SetLoadInBackground(bool aLoadInBackground) override;
   void Suspend() override;
   void Resume() override;
 
 private:
   MediaResource* GetResource() const override final;
 

--- a/dom/media/MediaDecoder.cpp
+++ b/dom/media/MediaDecoder.cpp
@@ -695,25 +695,16 @@ MediaDecoder::CallSeek(const SeekTarget&
 double
 MediaDecoder::GetCurrentTime()
 {
   MOZ_ASSERT(NS_IsMainThread());
   AbstractThread::AutoEnter context(AbstractMainThread());
   return mLogicalPosition;
 }
 
-already_AddRefed<nsIPrincipal>
-MediaDecoder::GetCurrentPrincipal()
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  MediaResource* r = GetResource();
-  AbstractThread::AutoEnter context(AbstractMainThread());
-  return r ? r->GetCurrentPrincipal() : nullptr;
-}
-
 void
 MediaDecoder::OnMetadataUpdate(TimedMetadata&& aMetadata)
 {
   MOZ_ASSERT(NS_IsMainThread());
   AbstractThread::AutoEnter context(AbstractMainThread());
   GetOwner()->RemoveMediaTracks();
   MetadataLoaded(MakeUnique<MediaInfo>(*aMetadata.mInfo),
                  UniquePtr<MetadataTags>(aMetadata.mTags.forget()),

--- a/dom/media/MediaDecoder.h
+++ b/dom/media/MediaDecoder.h
@@ -116,17 +116,17 @@ public:
   // The decoder should notify its owner to drop the reference to the decoder
   // to prevent further calls into the decoder.
   void NotifyXPCOMShutdown();
 
   // Called if the media file encounters a network error.
   void NetworkError();
 
   // Return the principal of the current URI being played or downloaded.
-  virtual already_AddRefed<nsIPrincipal> GetCurrentPrincipal();
+  virtual already_AddRefed<nsIPrincipal> GetCurrentPrincipal() = 0;
 
   // Return the time position in the video stream being
   // played measured in seconds.
   virtual double GetCurrentTime();
 
   // Seek to the time position in (seconds) from the start of the video.
   // If aDoFastSeek is true, we'll seek to the sync point/keyframe preceeding
   // the seek target.

--- a/dom/media/hls/HLSDecoder.cpp
+++ b/dom/media/hls/HLSDecoder.cpp
@@ -87,16 +87,23 @@ HLSDecoder::Load(nsIChannel* aChannel)
   }
 
   SetStateMachine(CreateStateMachine());
   NS_ENSURE_TRUE(GetStateMachine(), NS_ERROR_FAILURE);
 
   return InitializeStateMachine();
 }
 
+already_AddRefed<nsIPrincipal>
+HLSDecoder::GetCurrentPrincipal()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  return mResource ? mResource->GetCurrentPrincipal() : nullptr;
+}
+
 nsresult
 HLSDecoder::Play()
 {
   MOZ_ASSERT(NS_IsMainThread());
   HLS_DEBUG("HLSDecoder", "MediaElement called Play");
   auto resourceWrapper = mResource->GetResourceWrapper();
   resourceWrapper->Play();
   return MediaDecoder::Play();

--- a/dom/media/hls/HLSDecoder.h
+++ b/dom/media/hls/HLSDecoder.h
@@ -32,16 +32,17 @@ public:
   static bool IsSupportedType(const MediaContainerType& aContainerType);
 
   nsresult Load(nsIChannel* aChannel);
 
   nsresult Play() override;
 
   void Pause() override;
 
+  already_AddRefed<nsIPrincipal> GetCurrentPrincipal() override;
   bool IsTransportSeekable() override { return true; }
   void Suspend() override;
   void Resume() override;
 
 private:
   MediaResource* GetResource() const override final;
 
   MediaDecoderStateMachine* CreateStateMachine();

--- a/dom/media/mediasource/MediaSourceDecoder.cpp
+++ b/dom/media/mediasource/MediaSourceDecoder.cpp
@@ -357,12 +357,19 @@ MediaSourceDecoder::NotifyInitDataArrive
   MOZ_ASSERT(NS_IsMainThread());
   AbstractThread::AutoEnter context(AbstractMainThread());
 
   if (mDemuxer) {
     mDemuxer->NotifyInitDataArrived();
   }
 }
 
+already_AddRefed<nsIPrincipal>
+MediaSourceDecoder::GetCurrentPrincipal()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  return mResource ? mResource->GetCurrentPrincipal() : nullptr;
+}
+
 #undef MSE_DEBUG
 #undef MSE_DEBUGV
 
 } // namespace mozilla

--- a/dom/media/mediasource/MediaSourceDecoder.h
+++ b/dom/media/mediasource/MediaSourceDecoder.h
@@ -44,16 +44,18 @@ public:
   void SetInitialDuration(int64_t aDuration);
   void SetMediaSourceDuration(double aDuration);
 
   MediaSourceDemuxer* GetDemuxer()
   {
     return mDemuxer;
   }
 
+  already_AddRefed<nsIPrincipal> GetCurrentPrincipal() override;
+
   bool IsTransportSeekable() override { return true; }
 
   // Returns a string describing the state of the MediaSource internal
   // buffered data. Used for debugging purposes.
   void GetMozDebugReaderData(nsACString& aString) override;
 
   void AddSizeOfResources(ResourceSizes* aSizes) override;