Avoid needless int64_t to intptr_t conversion in eventhandler.

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 BIN_EVENTHANDLER_H_
 #define BIN_EVENTHANDLER_H_
 
 #include "bin/builtin.h"
 #include "bin/isolate_data.h"
 
@@ skipping 22 matching lines @@
 #elif defined(TARGET_OS_MACOS)
 #include "bin/eventhandler_macos.h"
 #elif defined(TARGET_OS_WINDOWS)
 #include "bin/eventhandler_win.h"
 #else
 #error Unknown target os.
 #endif
 
 class EventHandler {
  public:
-  void SendData(intptr_t id, Dart_Port dart_port, intptr_t data) {
+  void SendData(intptr_t id, Dart_Port dart_port, int64_t data) {
     delegate_.SendData(id, dart_port, data);
   }
 
   void Shutdown() {
     delegate_.Shutdown();
   }
 
   static EventHandler* Start() {
     EventHandler* handler = new EventHandler();
     handler->delegate_.Start();
     IsolateData* isolate_data =
         reinterpret_cast<IsolateData*>(Dart_CurrentIsolateData());
     isolate_data->event_handler = handler;
     return handler;
   }
 
  private:
   EventHandlerImplementation delegate_;
 };
 
 
 #endif  // BIN_EVENTHANDLER_H_