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

remoting/host/desktop_process.cc

Index: remoting/host/desktop_process.cc
diff --git a/remoting/host/desktop_process.cc b/remoting/host/desktop_process.cc
index a994e2207dce8d50d82b79a41a75275acdc03e09..f740a2bf909dc893357cd7ed1c58234711638f5b 100644
--- a/remoting/host/desktop_process.cc
+++ b/remoting/host/desktop_process.cc
@@ -61,6 +61,8 @@ bool DesktopProcess::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(ChromotingDaemonDesktopMsg_Crash, OnCrash)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
+
+  CHECK(handled) << "Received unexpected IPC type: " << message.type();
   return handled;
 }