--- a/dom/media/ChannelMediaDecoder.cpp
+++ b/dom/media/ChannelMediaDecoder.cpp
@@ -162,19 +162,19 @@ ChannelMediaDecoder::NotifyPrincipalChan
     // We'll receive one notification when the channel's initial principal
     // is known, after all HTTP redirects have resolved. This isn't really a
     // principal change, so return here to avoid the mSameOriginMedia check
     // below.
     mInitialChannelPrincipalKnown = true;
     return;
   }
   if (!mSameOriginMedia &&
-      DecoderTraits::CrossOriginRedirectsProhibited(ContainerType())) {
-    // For some content types we block mid-flight channel redirects to cross
-    // origin destinations due to security constraints. See bug 1441153.
+      Preferences::GetBool("media.block-midflight-redirects", true)) {
+    // Block mid-flight redirects to non CORS same origin destinations.
+    // See bugs 1441153, 1443942.
     LOG("ChannnelMediaDecoder prohibited cross origin redirect blocked.");
     NetworkError(MediaResult(NS_ERROR_DOM_BAD_URI,
                              "Prohibited cross origin redirect blocked"));
   }
 }
 
 void
 ChannelMediaDecoder::ResourceCallback::NotifySuspendedStatusChanged(

--- a/dom/media/ChannelMediaResource.cpp
+++ b/dom/media/ChannelMediaResource.cpp
@@ -280,16 +280,21 @@ ChannelMediaResource::OnStartRequest(nsI
     // Not an HTTP channel. Assume data will be sent from position zero.
     startOffset = 0;
   }
 
   // Update principals before OnDataAvailable() putting the data in the cache.
   // This is important, we want to make sure all principals are updated before
   // any consumer can see the new data.
   UpdatePrincipal();
+  if (owner->HasError()) {
+    // Updating the principal resulted in an error. Abort the load.
+    CloseChannel();
+    return NS_OK;
+  }
 
   mCacheStream.NotifyDataStarted(mLoadID, startOffset, seekable, length);
   mIsTransportSeekable = seekable;
 
   mSuspendAgent.Delegate(mChannel);
 
   // Fires an initial progress event.
   owner->DownloadProgressed();

--- a/dom/media/DecoderTraits.cpp
+++ b/dom/media/DecoderTraits.cpp
@@ -320,16 +320,9 @@ bool DecoderTraits::IsSupportedInVideoDo
     ADTSDecoder::IsSupportedType(*type) ||
     FlacDecoder::IsSupportedType(*type) ||
 #ifdef MOZ_ANDROID_HLS_SUPPORT
     HLSDecoder::IsSupportedType(*type) ||
 #endif
     false;
 }
 
-/* static */
-bool
-DecoderTraits::CrossOriginRedirectsProhibited(const MediaContainerType& aType)
-{
-  return WaveDecoder::IsSupportedType(aType);
-}
-
 } // namespace mozilla

--- a/dom/media/DecoderTraits.h
+++ b/dom/media/DecoderTraits.h
@@ -52,18 +52,14 @@ public:
 
   // Returns true if aType is MIME type of hls.
   static bool IsHttpLiveStreamingType(const MediaContainerType& aType);
 
   // Returns true if aType is matroska type.
   static bool IsMatroskaType(const MediaContainerType& aType);
 
   static bool IsSupportedType(const MediaContainerType& aType);
-
-  // For some content types we block channel redirects to cross origin
-  // destinations due to security constraints. See bug 1441153.
-  static bool CrossOriginRedirectsProhibited(const MediaContainerType& aType);
 };
 
 } // namespace mozilla
 
 #endif
 

--- a/dom/media/MediaPrefs.h
+++ b/dom/media/MediaPrefs.h
@@ -192,16 +192,17 @@ private:
 
   // resume background video decoding when the cursor is hovering over the tab.
   DECL_MEDIA_PREF("media.resume-bkgnd-video-on-tabhover",     ResumeVideoDecodingOnTabHover, bool, false);
 
   DECL_MEDIA_PREF("media.videocontrols.lock-video-orientation",  VideoOrientationLockEnabled, bool, false);
 
   // Media Seamless Looping
   DECL_MEDIA_PREF("media.seamless-looping",                   SeamlessLooping, bool, true);
+
 public:
   // Manage the singleton:
   static MediaPrefs& GetSingleton();
   static bool SingletonExists();
 
 private:
   template<class T> friend class StaticAutoPtr;
   static StaticAutoPtr<MediaPrefs> sInstance;