diff -r 000000000000 -r 6474c204b198 ipc/ipdl/test/cxx/IPDLUnitTestUtils.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ipc/ipdl/test/cxx/IPDLUnitTestUtils.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,27 @@
+
+#ifndef mozilla__ipdltest_IPDLUnitTestUtils
+#define mozilla__ipdltest_IPDLUnitTestUtils 1
+
+namespace mozilla {
+namespace _ipdltest {
+
+struct Bad {};
+
+} // namespace _ipdltest
+} // namespace mozilla
+
+namespace IPC {
+
+template<>
+struct ParamTraits<mozilla::_ipdltest::Bad>
+{
+  typedef mozilla::_ipdltest::Bad paramType;
+
+  // Defined in TestActorPunning.cpp.
+  static void Write(Message* aMsg, const paramType& aParam);
+  static bool Read(const Message* aMsg, void** aIter, paramType* aResult);
+};
+
+} // namespace IPC
+
+#endif // mozilla__ipdltest_IPDLUnitTestUtils