--- a/content/html/content/src/HTMLMediaElement.cpp
+++ b/content/html/content/src/HTMLMediaElement.cpp
@@ -3246,26 +3246,19 @@ already_AddRefed<nsIPrincipal> HTMLMedia
     nsRefPtr<nsIPrincipal> principal = mSrcStream->GetPrincipal();
     return principal.forget();
   }
   return nullptr;
 }
 
 void HTMLMediaElement::NotifyDecoderPrincipalChanged()
 {
-  nsRefPtr<nsIPrincipal> principal = GetCurrentPrincipal();
-
-  if (mDecoder) {
-    bool subsumes;
-    mDecoder->UpdateSameOriginStatus(
-      NS_SUCCEEDED(NodePrincipal()->Subsumes(principal, &subsumes)) && subsumes);
-  }
-
   for (uint32_t i = 0; i < mOutputStreams.Length(); ++i) {
     OutputMediaStream* ms = &mOutputStreams[i];
+    nsRefPtr<nsIPrincipal> principal = GetCurrentPrincipal();
     ms->mStream->CombineWithPrincipal(principal);
   }
 }
 
 void HTMLMediaElement::UpdateMediaSize(nsIntSize size)
 {
   mMediaSize = size;
 }

--- a/content/media/MediaDecoder.cpp
+++ b/content/media/MediaDecoder.cpp
@@ -363,17 +363,16 @@ MediaDecoder::MediaDecoder() :
   mCurrentTime(0.0),
   mInitialVolume(0.0),
   mInitialPlaybackRate(1.0),
   mInitialPreservesPitch(true),
   mRequestedSeekTime(-1.0),
   mDuration(-1),
   mTransportSeekable(true),
   mMediaSeekable(true),
-  mSameOriginMedia(false),
   mReentrantMonitor("media.decoder"),
   mIsDormant(false),
   mPlayState(PLAY_STATE_PAUSED),
   mNextState(PLAY_STATE_PAUSED),
   mCalledResourceLoaded(false),
   mIgnoreProgressData(false),
   mInfiniteStream(false),
   mTriggerPlaybackEndedWhenSourceStreamFinishes(false),
@@ -838,28 +837,16 @@ void MediaDecoder::DecodeError()
     return;
 
   if (mOwner)
     mOwner->DecodeError();
 
   Shutdown();
 }
 
-void MediaDecoder::UpdateSameOriginStatus(bool aSameOrigin)
-{
-  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
-  mSameOriginMedia = aSameOrigin;
-}
-
-bool MediaDecoder::IsSameOriginMedia()
-{
-  GetReentrantMonitor().AssertCurrentThreadIn();
-  return mSameOriginMedia;
-}
-
 bool MediaDecoder::IsSeeking() const
 {
   MOZ_ASSERT(NS_IsMainThread());
   return mPlayState == PLAY_STATE_SEEKING;
 }
 
 bool MediaDecoder::IsEnded() const
 {

--- a/content/media/MediaDecoder.h
+++ b/content/media/MediaDecoder.h
@@ -635,20 +635,16 @@ public:
   virtual void NotifyPlaybackStopped() {
     GetReentrantMonitor().AssertCurrentThreadIn();
     mPlaybackStatistics.Stop();
   }
 
   // The actual playback rate computation. The monitor must be held.
   virtual double ComputePlaybackRate(bool* aReliable);
 
-  // Return true when the media is same-origin with the element. The monitor
-  // must be held.
-  bool IsSameOriginMedia();
-
   // Returns true if we can play the entire media through without stopping
   // to buffer, given the current download and playback rates.
   bool CanPlayThrough();
 
   // Make the decoder state machine update the playback position. Called by
   // the reader on the decoder thread (Assertions for this checked by
   // mDecoderStateMachine). This must be called with the decode monitor
   // held.
@@ -735,19 +731,16 @@ public:
   // Called when a "MozAudioAvailable" event listener is added. This enables
   // the decoder to only dispatch "MozAudioAvailable" events when a
   // handler exists, reducing overhead. Called on the main thread.
   virtual void NotifyAudioAvailableListener();
 
   // Notifies the element that decoding has failed.
   virtual void DecodeError();
 
-  // Indicate whether the media is same-origin with the element.
-  void UpdateSameOriginStatus(bool aSameOrigin);
-
   MediaDecoderOwner* GetOwner() MOZ_OVERRIDE;
 
 #ifdef MOZ_RAW
   static bool IsRawEnabled();
 #endif
 
 #ifdef MOZ_OGG
   static bool IsOggEnabled();
@@ -960,20 +953,16 @@ public:
 
   // True if the resource is seekable at a transport level (server supports byte
   // range requests, local file, etc.).
   bool mTransportSeekable;
 
   // True if the media is seekable (i.e. supports random access).
   bool mMediaSeekable;
 
-  // True if the media is same-origin with the element. Data can only be
-  // passed to MediaStreams when this is true.
-  bool mSameOriginMedia;
-
   /******
    * The following member variables can be accessed from any thread.
    ******/
 
   // The state machine object for handling the decoding. It is safe to
   // call methods of this object from other threads. Its internal data
   // is synchronised on a monitor. The lifetime of this object is
   // after mPlayState is LOADING and before mPlayState is SHUTDOWN. It

--- a/content/media/MediaDecoderStateMachine.cpp
+++ b/content/media/MediaDecoderStateMachine.cpp
@@ -614,20 +614,16 @@ void MediaDecoderStateMachine::SendStrea
 
   DecodedStreamData* stream = mDecoder->GetDecodedStream();
   if (!stream)
     return;
 
   if (mState == DECODER_STATE_DECODING_METADATA)
     return;
 
-  if (!mDecoder->IsSameOriginMedia()) {
-    return;
-  }
-
   // If there's still an audio thread alive, then we can't send any stream
   // data yet since both SendStreamData and the audio thread want to be in
   // charge of popping the audio queue. We're waiting for the audio thread
   // to die before sending anything to our stream.
   if (mAudioThread)
     return;
 
   int64_t minLastAudioPacketTime = INT64_MAX;