diff -r 000000000000 -r 6474c204b198 xpcom/glue/nsISupportsImpl.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/glue/nsISupportsImpl.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 "nsISupportsImpl.h"
+
+nsresult NS_FASTCALL
+NS_TableDrivenQI(void* aThis, REFNSIID aIID, void **aInstancePtr,
+                 const QITableEntry* entries)
+{
+  do {
+    if (aIID.Equals(*entries->iid)) {
+      nsISupports* r =
+        reinterpret_cast<nsISupports*>
+                        (reinterpret_cast<char*>(aThis) + entries->offset);
+      NS_ADDREF(r);
+      *aInstancePtr = r;
+      return NS_OK;
+    }
+
+    ++entries;
+  } while (entries->iid);
+
+  *aInstancePtr = nullptr;
+  return NS_ERROR_NO_INTERFACE;
+}