diff -r 000000000000 -r 6474c204b198 netwerk/base/src/nsStreamListenerWrapper.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/netwerk/base/src/nsStreamListenerWrapper.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,26 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsStreamListenerWrapper.h"
+#ifdef DEBUG
+#include "MainThreadUtils.h"
+#endif
+
+NS_IMPL_ISUPPORTS(nsStreamListenerWrapper,
+                  nsIStreamListener,
+                  nsIRequestObserver,
+                  nsIThreadRetargetableStreamListener)
+
+NS_IMETHODIMP
+nsStreamListenerWrapper::CheckListenerChain()
+{
+    NS_ASSERTION(NS_IsMainThread(), "Should be on main thread!");
+    nsresult rv = NS_OK;
+    nsCOMPtr<nsIThreadRetargetableStreamListener> retargetableListener =
+        do_QueryInterface(mListener, &rv);
+    if (retargetableListener) {
+        rv = retargetableListener->CheckListenerChain();
+    }
+    return rv;
+}