Crash the network or desktop process when an unknown IPC message is received.

remoting/host/desktop_session_win.cc

Index: remoting/host/desktop_session_win.cc
diff --git a/remoting/host/desktop_session_win.cc b/remoting/host/desktop_session_win.cc
index 182111d9cd23702a9b31571bb204ed937771768d..04bd1f11a071c675705ce8f23ef0f5550cbddb58 100644
--- a/remoting/host/desktop_session_win.cc
+++ b/remoting/host/desktop_session_win.cc
@@ -82,6 +82,12 @@ bool DesktopSessionWin::OnMessageReceived(const IPC::Message& message) {
                         OnInjectSas)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
+
+  if (!handled) {
+    LOG(ERROR) << "An unexpected IPC message received: type=" << message.type();
+    RestartDesktopProcess(FROM_HERE);
+  }
+
   return handled;
 }