--- a/content/media/MediaResource.cpp
+++ b/content/media/MediaResource.cpp
@@ -310,25 +310,16 @@ ChannelMediaResource::OnStartRequest(nsI
 
     if (seekable) {
       mDecoder->SetInfinite(false);
     }
   }
   mDecoder->SetTransportSeekable(seekable);
   mCacheStream.SetTransportSeekable(seekable);
 
-  nsCOMPtr<nsICachingChannel> cc = do_QueryInterface(aRequest);
-  if (cc) {
-    bool fromCache = false;
-    rv = cc->IsFromCache(&fromCache);
-    if (NS_SUCCEEDED(rv) && !fromCache) {
-      cc->SetCacheAsFile(true);
-    }
-  }
-
   {
     MutexAutoLock lock(mLock);
     mChannelStatistics->Start();
   }
 
   mReopenOnError = false;
   // If we are seeking to get metadata, because we are playing an OGG file,
   // ignore if the channel gets closed without us suspending it explicitly. We