Revert 106677 (caused several PPAPI test timeouts, see http://crbug.com/101154)

ppapi/proxy/interface_proxy.h

 // Copyright (c) 2011 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 PPAPI_PROXY_INTERFACE_PROXY_H_
 #define PPAPI_PROXY_INTERFACE_PROXY_H_
 
 #include "base/basictypes.h"
 #include "ipc/ipc_channel.h"
 #include "ipc/ipc_message.h"
@@ skipping 42 matching lines @@
   virtual bool Send(IPC::Message* msg);
 
   // Sub-classes must implement IPC::Channel::Listener which contains this:
   //virtual bool OnMessageReceived(const IPC::Message& msg);
 
  protected:
   // Creates the given interface associated with the given dispatcher. The
   // dispatcher manages our lifetime.
   InterfaceProxy(Dispatcher* dispatcher);
 
+  uint32 SendCallback(PP_CompletionCallback callback);
+  PP_CompletionCallback ReceiveCallback(uint32 serialized_callback);
+
  private:
   Dispatcher* dispatcher_;
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_INTERFACE_PROXY_H_