Remove js_interop_3_test.dart which tests sync ports

tests/html/js_interop_3_test.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
-
-library JsInterop3Test;
-import '../../pkg/unittest/lib/unittest.dart';
-import '../../pkg/unittest/lib/html_config.dart';
-import 'dart:async';
-import 'dart:html';
-import 'dart:isolate';
-
-injectSource(code) {
-  final script = new ScriptElement();
-  script.type = 'text/javascript';
-  script.innerHtml = code;
-  document.body.append(script);
-}
-
-var jsToDart = """
-  var fun1 = window.lookupPort('fun1');
-  var result = fun1.callSync({'a': 'Hello', 'b': 'World', c: 42});
-
-  var fun2 = window.lookupPort('fun2');
-  fun2.callSync(result);
-""";
-
-main() {
-  useHtmlConfiguration();
-
-  test('js-to-dart', () {
-    var fun1 = (message) {
-      expect(message['a'], 'Hello');
-      expect(message['b'], 'World');
-      expect(message['c'], 42);
-      expect(message.keys.length, 3);
-      return 42;
-    };
-
-    var port1 = new ReceivePortSync();
-    port1.receive(fun1);
-    window.registerPort('fun1', port1.toSendPort());
-
-    // TODO(vsm): Investigate why this needs to be called asynchronously.
-    var done = expectAsync0(() {});
-    var fun2 = (message) {
-      expect(message, 42);
-      Timer.run(done);
-    };
-
-    var port2 = new ReceivePortSync();
-    port2.receive(fun2);
-    window.registerPort('fun2', port2.toSendPort());
-
-    injectSource(jsToDart);
-  });
-}