diff -r 000000000000 -r 6474c204b198 xpcom/glue/nsIInterfaceRequestorUtils.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/glue/nsIInterfaceRequestorUtils.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,31 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+
+nsresult
+nsGetInterface::operator()( const nsIID& aIID, void** aInstancePtr ) const
+{
+  nsresult status;
+
+  if ( mSource )
+  {
+    nsCOMPtr<nsIInterfaceRequestor> factoryPtr = do_QueryInterface(mSource, &status);
+
+    if ( factoryPtr )
+      status = factoryPtr->GetInterface(aIID, aInstancePtr);
+    else
+      status = NS_ERROR_NO_INTERFACE;
+  }
+  else
+    status = NS_ERROR_NULL_POINTER;
+
+  if ( NS_FAILED(status) )
+    *aInstancePtr = 0;
+  if ( mErrorPtr )
+    *mErrorPtr = status;
+  return status;
+}