Start better error reporting for sockets

tests/standalone/src/io/SocketCloseTest.dart

 // 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.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 //
 // Test socket close events.
@@ skipping 73 matching lines @@
           proceed();
           break;
         case 6:
           proceed();
           break;
         default:
           Expect.fail("Unknown test mode");
       }
     }
 
-    void errorHandler() {
+    void errorHandler(Exception e) {
       _errorEvents++;
       _socket.close();
     }
 
     void connectHandler() {
       _socket.onData = dataHandler;
       _socket.onClosed = closeHandler;
       _socket.onError = errorHandler;
 
       void writeHello() {
@@ skipping 167 matching lines @@
           default:
             Expect.fail("Unknown test mode");
         }
       }
 
       void closeHandler() {
         _closeEvents++;
         connection.close();
       }
 
-      void errorHandler() {
-        Expect.fail("Socket error");
+      void errorHandler(Exception e) {
+        Expect.fail("Socket error $e");
       }
 
       _iterations++;
 
       connection.onData = dataHandler;
       connection.onClosed = closeHandler;
       connection.onError = errorHandler;
     }
 
-    void errorHandlerServer() {
+    void errorHandlerServer(Exception e) {
       Expect.fail("Server socket error");
     }
 
     waitForResult(Timer timer) {
       // Make sure all iterations have been run. In multiple of these
       // scenarios it is possible to get the SERVERSHUTDOWN message
       // before we have received the last close event on the
       // server. In these cases we wait for the correct number of
       // close events.
       if (_iterations == ITERATIONS &&
@@ skipping 76 matching lines @@
   var tests = 7;
   var port = new ReceivePort();
   var completed = 0;
   port.receive((message, ignore) {
     if (++completed == tests) port.close();
   });
   for (var i = 0; i < tests; i++) {
     new SocketClose.start(i, port.toSendPort());
   }
 }