EDK: Add Core::DuplicateHandleWithReducedRights().

mojo/edk/system/mock_simple_dispatcher.cc

Index: mojo/edk/system/mock_simple_dispatcher.cc
diff --git a/mojo/edk/system/mock_simple_dispatcher.cc b/mojo/edk/system/mock_simple_dispatcher.cc
index 1c96f229890b1c6ac57079267af0270dba50e17c..58243c106e8c7988ec4f2ed3e01f2612c8a965b8 100644
--- a/mojo/edk/system/mock_simple_dispatcher.cc
+++ b/mojo/edk/system/mock_simple_dispatcher.cc
@@ -65,6 +65,12 @@ MockSimpleDispatcher::MockSimpleDispatcher(const HandleSignalsState& state)
 
 MockSimpleDispatcher::~MockSimpleDispatcher() {}
 
+MojoResult MockSimpleDispatcher::DuplicateDispatcherImplNoLock(
+    util::RefPtr<Dispatcher>* new_dispatcher) {
+  *new_dispatcher = MakeRefCounted<MockSimpleDispatcher>(state_);
+  return MOJO_RESULT_OK;
+}
+
 RefPtr<Dispatcher>
 MockSimpleDispatcher::CreateEquivalentDispatcherAndCloseImplNoLock(
     MessagePipe* /*message_pipe*/,