Bring in latest dart:io WebSocket code.

lib/src/copy/web_socket.dart

+// Copyright (c) 2015, 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.
+
+// The following code is copied from sdk/lib/io/websocket.dart. The "dart:io"
+// implementation isn't used directly to support non-"dart:io" applications.
+//
+// Because it's copied directly, only modifications necessary to support the
+// desired public API and to remove "dart:io" dependencies have been made.
+//
+// This is up-to-date as of sdk revision
+// 86227840d75d974feb238f8b3c59c038b99c05cf.
+library http_parser.copy.web_socket;
+
+/**
+ * Web socket status codes used when closing a web socket connection.
+ */
+abstract class WebSocketStatus {
+  static const int NORMAL_CLOSURE = 1000;
+  static const int GOING_AWAY = 1001;
+  static const int PROTOCOL_ERROR = 1002;
+  static const int UNSUPPORTED_DATA = 1003;
+  static const int RESERVED_1004  = 1004;
+  static const int NO_STATUS_RECEIVED = 1005;
+  static const int ABNORMAL_CLOSURE = 1006;
+  static const int INVALID_FRAME_PAYLOAD_DATA = 1007;
+  static const int POLICY_VIOLATION = 1008;
+  static const int MESSAGE_TOO_BIG = 1009;
+  static const int MISSING_MANDATORY_EXTENSION = 1010;
+  static const int INTERNAL_SERVER_ERROR = 1011;
+  static const int RESERVED_1015 = 1015;
+}
+
+abstract class WebSocket {
+  /**
+   * Possible states of the connection.
+   */
+  static const int CONNECTING = 0;
+  static const int OPEN = 1;
+  static const int CLOSING = 2;
+  static const int CLOSED = 3;
+}