Avoid needless int64_t to intptr_t conversion in eventhandler.

runtime/bin/eventhandler_win.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_EVENTHANDLER_WIN_H_
 #define BIN_EVENTHANDLER_WIN_H_
 
 #if !defined(BIN_EVENTHANDLER_H_)
 #error Do not include eventhandler_win.h directly; use eventhandler.h instead.
 #endif
@@ skipping 328 matching lines @@
   ClientSocket* next_;
 };
 
 
 // Event handler.
 class EventHandlerImplementation {
  public:
   EventHandlerImplementation();
   virtual ~EventHandlerImplementation() {}
 
-  void SendData(intptr_t id, Dart_Port dart_port, intptr_t data);
+  void SendData(intptr_t id, Dart_Port dart_port, int64_t data);
   void Start();
   void Shutdown();
 
   static void EventHandlerEntry(uword args);
 
   DWORD GetTimeout();
   void HandleInterrupt(InterruptMessage* msg);
   void HandleTimeout();
   void HandleAccept(ListenSocket* listen_socket, IOBuffer* buffer);
   void HandleClosed(Handle* handle);
   void HandleError(Handle* handle);
   void HandleRead(Handle* handle, int bytes, IOBuffer* buffer);
   void HandleWrite(Handle* handle, int bytes, IOBuffer* buffer);
   void HandleClose(ClientSocket* client_socket);
   void HandleIOCompletion(DWORD bytes, ULONG_PTR key, OVERLAPPED* overlapped);
 
   HANDLE completion_port() { return completion_port_; }
 
  private:
   ClientSocket* client_sockets_head_;
 
   int64_t timeout_;  // Time for next timeout.
   Dart_Port timeout_port_;
   bool shutdown_;
   HANDLE completion_port_;
 };
 
 
 #endif  // BIN_EVENTHANDLER_WIN_H_