Check if the connected socket id already exists for P2PSocketDispatcherHost::OnAcceptIncomingTcpCon…

content/browser/renderer_host/p2p/socket_dispatcher_host.cc

Index: content/browser/renderer_host/p2p/socket_dispatcher_host.cc
diff --git a/content/browser/renderer_host/p2p/socket_dispatcher_host.cc b/content/browser/renderer_host/p2p/socket_dispatcher_host.cc
index 913adf7710f14474db3d1c9a578f3a1c91b5a549..3a2a5ea64a7a23c75ff03431ccbaf56aa0e4bc06 100644
--- a/content/browser/renderer_host/p2p/socket_dispatcher_host.cc
+++ b/content/browser/renderer_host/p2p/socket_dispatcher_host.cc
@@ -262,9 +262,15 @@ void P2PSocketDispatcherHost::OnAcceptIncomingTcpConnection(
   P2PSocketHost* socket = LookupSocket(listen_socket_id);
   if (!socket) {
     LOG(ERROR) << "Received P2PHostMsg_AcceptIncomingTcpConnection "
-        "for invalid socket_id.";
+        "for invalid listen_socket_id.";
     return;
   }
+  if (LookupSocket(connected_socket_id) != NULL) {
+    LOG(ERROR) << "Received P2PHostMsg_AcceptIncomingTcpConnection "
+        "for duplicated connected_socket_id.";
+    return;
+  }
+
   P2PSocketHost* accepted_connection =
       socket->AcceptIncomingTcpConnection(remote_address, connected_socket_id);
   if (accepted_connection) {