Use native wrapper fields to store socket ids.

runtime/bin/socket.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef BIN_SOCKET_H_
 #define BIN_SOCKET_H_
 
 #include "bin/builtin.h"
 #include "bin/utils.h"
 
@@ skipping 18 matching lines @@
   enum SocketRequest {
     kLookupRequest = 0,
   };
 
   static bool Initialize();
   static intptr_t Available(intptr_t fd);
   static int Read(intptr_t fd, void* buffer, intptr_t num_bytes);
   static int Write(intptr_t fd, const void* buffer, intptr_t num_bytes);
   static intptr_t CreateConnect(const char* host, const intptr_t port);
   static intptr_t GetPort(intptr_t fd);
-  static bool GetRemotePeer(intptr_t fd, char *host, intptr_t *port);
+  static bool GetRemotePeer(intptr_t fd, char* host, intptr_t* port);
   static void GetError(intptr_t fd, OSError* os_error);
   static intptr_t GetStdioHandle(int num);
 
   // Perform a IPv4 hostname lookup. Returns the hostname string in
   // IPv4 dotted-decimal format.
   static const char* LookupIPv4Address(char* host, OSError** os_error);
 
   static Dart_Port GetServicePort();
 
+  static Dart_Handle SetSocketIdNativeField(Dart_Handle socket, intptr_t id);
+  static Dart_Handle GetSocketIdNativeField(Dart_Handle socket, intptr_t* id);
+
  private:
   static dart::Mutex mutex_;
   static int service_ports_size_;
   static Dart_Port* service_ports_;
   static int service_ports_index_;
 
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(Socket);
 };
 
@@ skipping 11 matching lines @@
   //   -5: invalid bindAddress
   static intptr_t CreateBindListen(const char* bindAddress,
                                    intptr_t port,
                                    intptr_t backlog);
 
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(ServerSocket);
 };
 
 #endif  // BIN_SOCKET_H_