net doesn't depend on libevent directly now.

net/base/listen_socket.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.
 
 // TCP/IP server that handles IO asynchronously in the specified MessageLoop.
 // These objects are NOT thread safe.  They use WSAEVENT handles to monitor
 // activity in a given MessageLoop.  This means that callbacks will
 // happen in that loop's thread always and that all other methods (including
 // constructors and destructors) should also be called from the same thread.
 
@@ skipping 12 matching lines @@
 #elif defined(OS_POSIX)
 #include "base/message_loop.h"
 #endif
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "net/base/net_api.h"
 
 #if defined(OS_POSIX)
-struct event;  // From libevent
 typedef int SOCKET;
 #endif
 
 // Implements a raw socket interface
 class NET_API ListenSocket : public base::RefCountedThreadSafe<ListenSocket>,
 #if defined(OS_WIN)
                              public base::win::ObjectWatcher::Delegate {
 #elif defined(OS_POSIX)
                              public MessageLoopForIO::Watcher {
 #endif
@@ skipping 80 matching lines @@
   ListenSocketDelegate *socket_delegate_;
 
  private:
   bool reads_paused_;
   bool has_pending_reads_;
 
   DISALLOW_COPY_AND_ASSIGN(ListenSocket);
 };
 
 #endif  // NET_BASE_LISTEN_SOCKET_H_