Add validation to construction of Cookie objects.

tests/standalone/io/http_headers_test.dart

 // Copyright (c) 2013, 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 dart.io;
 
 import "package:expect/expect.dart";
 import "dart:async";
 import "dart:collection";
 import "dart:convert";
@@ skipping 418 matching lines @@
   test("SID", "sJdkjKSJD12343kjKj78");
 }
 
 void testInvalidCookie() {
   Expect.throws(() => new _Cookie.fromSetCookieValue(""));
   Expect.throws(() => new _Cookie.fromSetCookieValue("="));
   Expect.throws(() => new _Cookie.fromSetCookieValue("=xxx"));
   Expect.throws(() => new _Cookie.fromSetCookieValue("xxx"));
   Expect.throws(() => new _Cookie.fromSetCookieValue(
       "xxx=yyy; expires=12 jan 2013"));
+  Expect.throws(() => new _Cookie.fromSetCookieValue("x x = y y"));
+  Expect.throws(() => new _Cookie("[4", "y"));
+  Expect.throws(() => new _Cookie("4", "y\""));
 
   _HttpHeaders headers = new _HttpHeaders("1.1");
   headers.set('Cookie',
               'DARTSESSID=d3d6fdd78d51aaaf2924c32e991f4349; undefined');
   Expect.equals('DARTSESSID', headers._parseCookies().single.name);
   Expect.equals('d3d6fdd78d51aaaf2924c32e991f4349',
                 headers._parseCookies().single.value);
 }
 
 void testHeaderLists() {
@@ skipping 10 matching lines @@
   testIfModifiedSince();
   testHost();
   testEnumeration();
   testHeaderValue();
   testContentType();
   testContentTypeCache();
   testCookie();
   testInvalidCookie();
   testHeaderLists();
 }