Cleanup: Remove unneeded forward declararations in net.

net/curvecp/messenger.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 NET_CURVECP_MESSENGER_H_
 #define NET_CURVECP_MESSENGER_H_
 #pragma once
 
 #include <deque>
 #include <list>
 
 #include "base/basictypes.h"
 #include "base/task.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/timer.h"
 #include "net/base/completion_callback.h"
 #include "net/curvecp/circular_buffer.h"
 #include "net/curvecp/packetizer.h"
 #include "net/curvecp/received_block_list.h"
 #include "net/curvecp/rtt_and_send_rate_calculator.h"
 #include "net/curvecp/sent_block_list.h"
 #include "net/socket/socket.h"
 
 namespace net {
 
-class DrainableIOBuffer;
 class IOBufferWithSize;
 class Packetizer;
 
 // The messenger provides the reliable CurveCP transport.
 class Messenger : public base::NonThreadSafe,
                   public Packetizer::Listener {
  public:
   explicit Messenger(Packetizer* packetizer);
   virtual ~Messenger();
 
@@ skipping 58 matching lines @@
 
   OldCompletionCallbackImpl<Messenger> send_message_callback_;
 
   ScopedRunnableMethodFactory<Messenger> factory_;
   DISALLOW_COPY_AND_ASSIGN(Messenger);
 };
 
 }  // namespace net
 
 #endif  // NET_CURVECP_MESSENGER_H_