Uses a finalizer to delete zlib filter resources

sdk/lib/io/websocket_impl.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.
 
 part of dart.io;
 
 const String _webSocketGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
 const String _clientNoContextTakeover = "client_no_context_takeover";
 const String _serverNoContextTakeover = "server_no_context_takeover";
 const String _clientMaxWindowBits = "client_max_window_bits";
@@ skipping 563 matching lines @@
     decoder.process(data, 0, data.length);
     var result = [];
     var out;
 
     while ((out = decoder.processed()) != null) {
       result.addAll(out);
     }
 
     if ((serverSide && clientNoContextTakeover) ||
         (!serverSide && serverNoContextTakeover)) {
-      decoder.end();
       decoder = null;
     }
 
     return new Uint8List.fromList(result);
   }
 
   List<int> processOutgoingMessage(List<int> msg) {
     _ensureEncoder();
     var result = [];
     Uint8List buffer;
@@ skipping 12 matching lines @@
     }
 
     encoder.process(buffer, 0, buffer.length);
 
     while ((out = encoder.processed()) != null) {
       result.addAll(out);
     }
 
     if ((!serverSide && clientNoContextTakeover) ||
         (serverSide && serverNoContextTakeover)) {
-      encoder.end();
       encoder = null;
     }
 
     if (result.length > 4) {
       result = result.sublist(0, result.length - 4);
     }
 
     return result;
   }
 }
@@ skipping 615 matching lines @@
     return code != null &&
         (code < WebSocketStatus.NORMAL_CLOSURE ||
             code == WebSocketStatus.RESERVED_1004 ||
             code == WebSocketStatus.NO_STATUS_RECEIVED ||
             code == WebSocketStatus.ABNORMAL_CLOSURE ||
             (code > WebSocketStatus.INTERNAL_SERVER_ERROR &&
                 code < WebSocketStatus.RESERVED_1015) ||
             (code >= WebSocketStatus.RESERVED_1015 && code < 3000));
   }
 }