Add CHECK() in UdpSocketLibevent to debug crbug.com/452121

net/udp/udp_server_socket.h

 // Copyright (c) 2012 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_SOCKET_UDP_SERVER_SOCKET_H_
 #define NET_SOCKET_UDP_SERVER_SOCKET_H_
 
 #include "net/base/completion_callback.h"
 #include "net/base/net_util.h"
 #include "net/udp/datagram_server_socket.h"
@@ skipping 15 matching lines @@
   int RecvFrom(IOBuffer* buf,
                int buf_len,
                IPEndPoint* address,
                const CompletionCallback& callback) override;
   int SendTo(IOBuffer* buf,
              int buf_len,
              const IPEndPoint& address,
              const CompletionCallback& callback) override;
   int SetReceiveBufferSize(int32 size) override;
   int SetSendBufferSize(int32 size) override;
-  void Close() override;
+  int Close() override;
   int GetPeerAddress(IPEndPoint* address) const override;
   int GetLocalAddress(IPEndPoint* address) const override;
   const BoundNetLog& NetLog() const override;
   void AllowAddressReuse() override;
   void AllowBroadcast() override;
   int JoinGroup(const IPAddressNumber& group_address) const override;
   int LeaveGroup(const IPAddressNumber& group_address) const override;
   int SetMulticastInterface(uint32 interface_index) override;
   int SetMulticastTimeToLive(int time_to_live) override;
   int SetMulticastLoopbackMode(bool loopback) override;
   int SetDiffServCodePoint(DiffServCodePoint dscp) override;
   void DetachFromThread() override;
 
 #if defined(OS_WIN)
   // Switch to use non-blocking IO. Must be called right after construction and
   // before other calls.
   void UseNonBlockingIO();
 #endif
 
  private:
   UDPSocket socket_;
   bool allow_address_reuse_;
   bool allow_broadcast_;
   DISALLOW_COPY_AND_ASSIGN(UDPServerSocket);
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_UDP_SERVER_SOCKET_H_