Mojo cpp bindings: add support for validating incoming messages.

mojo/public/cpp/bindings/no_interface.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_NO_INTERFACE_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_NO_INTERFACE_H_
 
 #include <assert.h>
 
 #include "mojo/public/cpp/bindings/message.h"
 #include "mojo/public/cpp/system/core.h"
 
 namespace mojo {
 
+// NoValidator is for use in cases when message validation is not needed.
+class NoValidator {
+};
+
 // NoInterface is for use in cases when a non-existent or empty interface is
 // needed (e.g., when the Mojom "Peer" attribute is not present).
 
 class NoInterfaceProxy;
 class NoInterfaceStub;
 
 class NoInterface {
  public:
   typedef NoInterfaceProxy Proxy_;
   typedef NoInterfaceStub Stub_;
+  typedef NoValidator RequestValidator_;
+  typedef NoValidator ResponseValidator_;
   typedef NoInterface Client_;
   virtual ~NoInterface() {}
   virtual void SetClient(NoInterface* client) {}
 };
 
 class NoInterfaceProxy : public NoInterface {
  public:
   explicit NoInterfaceProxy(MessageReceiver* receiver) {}
 };
 
 class NoInterfaceStub : public MessageReceiver {
  public:
   NoInterfaceStub() {}
   void set_sink(NoInterface* sink) {}
   virtual bool Accept(Message* message) MOJO_OVERRIDE;
   virtual bool AcceptWithResponder(Message* message, MessageReceiver* responder)
       MOJO_OVERRIDE;
 };
 
 
 // AnyInterface is for use in cases where any interface would do (e.g., see the
 // Shell::Connect method).
 
 typedef NoInterface AnyInterface;
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_NO_INTERFACE_H_