Add reverse dns lookup as a method on InternetAddress.

runtime/bin/socket.h

 // Copyright (c) 2013, 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 132 matching lines @@
   T** addresses_;
 
   DISALLOW_COPY_AND_ASSIGN(AddressList);
 };
 
 class Socket {
  public:
   enum SocketRequest {
     kLookupRequest = 0,
     kListInterfacesRequest = 1,
+    kReverseLookupRequest = 2,
   };
 
   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 Create(RawAddr addr);
   static intptr_t Connect(intptr_t fd, RawAddr addr, const intptr_t port);
   static intptr_t CreateConnect(RawAddr addr,
                                 const intptr_t port);
   static intptr_t GetPort(intptr_t fd);
   static bool GetRemotePeer(intptr_t fd, char* host, intptr_t* port);
   static void GetError(intptr_t fd, OSError* os_error);
   static int GetType(intptr_t fd);
   static intptr_t GetStdioHandle(int num);
   static void Close(intptr_t fd);
   static bool SetNonBlocking(intptr_t fd);
   static bool SetBlocking(intptr_t fd);
   static bool SetNoDelay(intptr_t fd, bool enabled);
 
   // Perform a hostname lookup. Returns a AddressList of SocketAddress's.
   static AddressList<SocketAddress>* LookupAddress(const char* host,
                                                    int type,
                                                    OSError** os_error);
+  static const char* ReverseLookup(RawAddr addr, OSError** os_error);
 
   // List interfaces. Returns a AddressList of InterfaceSocketAddress's.
   static AddressList<InterfaceSocketAddress>* ListInterfaces(
       int type,
       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);
@@ skipping 27 matching lines @@
 
  private:
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(ServerSocket);
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_SOCKET_H_