Consistently use setters to set event handlers in native APIs.

tests/standalone/src/SocketCloseTest.dart

 // Copyright (c) 2011, 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.
 //
 // Test socket close events.
 
 class SocketCloseTest {
 
   static void testMain() {
     SocketClose socketClose = new SocketClose.start();
@@ skipping 35 matching lines @@
         shutdown();
       }
     }
 
     void errorHandler() {
       _errorEvents++;
       _socket.close();
     }
 
     void connectHandler() {
-      _socket.setDataHandler(dataHandler);
-      _socket.setCloseHandler(closeHandler);
-      _socket.setErrorHandler(errorHandler);
+      _socket.dataHandler = dataHandler;
+      _socket.closeHandler = closeHandler;
+      _socket.errorHandler = errorHandler;
 
       if ((_iterations % 2) == 0) {
         _socket.writeList("Hello".charCodes(), 0, 5);
       }
     }
 
     _socket = new Socket(SocketCloseServer.HOST, _port);
     Expect.equals(true, _socket !== null);
-    _socket.setConnectHandler(connectHandler);
+    _socket.connectHandler = connectHandler;
   }
 
   void start() {
     _receivePort.receive((var message, SendPort replyTo) {
       _port = message;
       sendData();
     });
     _sendPort.send(SERVERINIT, _receivePort.toSendPort());
   }
 
@@ skipping 43 matching lines @@
 
       void errorHandler() {
         _errorEvents++;
         _client.close();
       }
 
       _client = _server.accept();
       if ((_iterations % 2) == 1) {
         _client.close();
       }
-      _client.setDataHandler(messageHandler);
-      _client.setCloseHandler(closeHandler);
-      _client.setErrorHandler(errorHandler);
+      _client.dataHandler = messageHandler;
+      _client.closeHandler = closeHandler;
+      _client.errorHandler = errorHandler;
       _iterations++;
     }
 
     void errorHandlerServer() {
       _server.close();
     }
 
     this.port.receive((message, SendPort replyTo) {
       if (message == SocketClose.SERVERINIT) {
         _errorEvents = 0;
         _dataEvents = 0;
         _closeEvents = 0;
         _iterations = 0;
         _server = new ServerSocket(HOST, 0, 10);
         Expect.equals(true, _server !== null);
-        _server.setConnectionHandler(connectionHandler);
-        _server.setErrorHandler(errorHandlerServer);
+        _server.connectionHandler = connectionHandler;
+        _server.errorHandler = errorHandlerServer;
         replyTo.send(_server.port, null);
       } else if (message == SocketClose.SERVERSHUTDOWN) {
         Expect.equals(SocketClose.ITERATIONS/2, _dataEvents);
         Expect.equals(0, _closeEvents);
         Expect.equals(0, _errorEvents);
         _server.close();
         this.port.close();
       }
     });
   }
 
   ServerSocket _server;
   int _errorEvents;
   int _dataEvents;
   int _closeEvents;
   int _iterations;
 }
 
 
 main() {
   SocketCloseTest.testMain();
 }