ipc_channel: warn if someone forgets to check the result of Connect()

ipc/ipc_channel.h

 // Copyright (c) 2010 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 IPC_IPC_CHANNEL_H_
 #define IPC_IPC_CHANNEL_H_
 #pragma once
 
+#include "base/compiler_specific.h"
 #include "ipc/ipc_message.h"
 
 namespace IPC {
 
 //------------------------------------------------------------------------------
 
 class Channel : public Message::Sender {
   // Security tests need access to the pipe handle.
   friend class ChannelTest;
 
@@ skipping 41 matching lines @@
   //
   Channel(const std::string& channel_id, Mode mode, Listener* listener);
 
   ~Channel();
 
   // Connect the pipe.  On the server side, this will initiate
   // waiting for connections.  On the client, it attempts to
   // connect to a pre-existing pipe.  Note, calling Connect()
   // will not block the calling thread and may complete
   // asynchronously.
-  bool Connect();
+  bool Connect() WARN_UNUSED_RESULT;
 
   // Close this Channel explicitly.  May be called multiple times.
   void Close();
 
   // Modify the Channel's listener.
   void set_listener(Listener* listener);
 
   // Send a message over the Channel to the listener on the other end.
   //
   // |message| must be allocated using operator new.  This object will be
@@ skipping 31 matching lines @@
     HELLO_MESSAGE_TYPE = kuint16max  // Maximum value of message type (uint16),
                                      // to avoid conflicting with normal
                                      // message types, which are enumeration
                                      // constants starting from 0.
   };
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_H_