[dart:io] Adds a finalizer to _NativeSocket to avoid socket leaks

runtime/bin/eventhandler.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 RUNTIME_BIN_EVENTHANDLER_H_
 #define RUNTIME_BIN_EVENTHANDLER_H_
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 #include "bin/isolate_data.h"
@@ skipping 629 matching lines @@
   static void Start();
 
   /**
    * Stop the event-handler. It's expected that there will be no further calls
    * to SendData after a call to Stop.
    */
   static void Stop();
 
   static EventHandlerImplementation* delegate();
 
+  static void SendFromNative(intptr_t id, Dart_Port port, int64_t data);
+
  private:
   friend class EventHandlerImplementation;
   EventHandlerImplementation delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(EventHandler);
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // RUNTIME_BIN_EVENTHANDLER_H_