Add P2PDatagramSocket and P2PStreamSocket interfaces.

remoting/protocol/p2p_socket.h

+// Copyright 2015 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 REMOTING_PROTOCOL_P2P_SOCKET_H_
+#define REMOTING_PROTOCOL_P2P_SOCKET_H_
+
+#include "net/socket/socket.h"
+
+namespace remoting {
+namespace protocol {
+
+// Peer-to-peer socket with stream semantics.
+class P2PStreamSocket : public net::Socket {};

[Wez, 2015/06/22 15:49:07]

As noted before, is there any value in deriving from net::Socket?

[Sergey Ulanov, 2015/07/10 00:49:54]

No. Rewrote these so they don't depend on net and now P2PStreamSocket and 
P2PDatagramSocket  are not related to each other. The only problem was that they
were used with BufferedSocketWriter which we still want to use with regular TCP
socket - solved that by passing Write() callback to BufferedSocketWriter instead
of net::Socket*.

+
+// Peer-to-peer socket with datagram semantics.
+class P2PDatagramSocket : public net::Socket {};
+
+}  // namespace protocol
+}  // namespace remoting
+
+#endif  // REMOTING_PROTOCOL_P2P_SOCKET_H_