Move P2P code to content namespace.

content/common/p2p_sockets.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.
 
 // This file defines some basic types used by the P2P-related IPC
 // messages.
 
 #ifndef CONTENT_COMMON_P2P_SOCKETS_H_
 #define CONTENT_COMMON_P2P_SOCKETS_H_
 
+namespace content {
+
 // Type of P2P Socket.
 enum P2PSocketType {
   P2P_SOCKET_UDP,
   P2P_SOCKET_TCP_SERVER,
   P2P_SOCKET_TCP_CLIENT,
 };
 
+}  // namespace content
+
 #endif  // CONTENT_COMMON_P2P_SOCKETS_H_