| Index: sdk/lib/io/websocket_impl.dart | 
| diff --git a/sdk/lib/io/websocket_impl.dart b/sdk/lib/io/websocket_impl.dart | 
| index 2d29a5f658dd1c0dee32a68a58f14b5a3840ba23..bd21220f69830e9179419dd6ce6a5421bf7d9652 100644 | 
| --- a/sdk/lib/io/websocket_impl.dart | 
| +++ b/sdk/lib/io/websocket_impl.dart | 
| @@ -683,9 +683,9 @@ class _WebSocketImpl extends Stream implements WebSocket { | 
| } | 
| assert(index == headerSize); | 
| try { | 
| -      _socket.writeBytes(header); | 
| +      _socket.add(header); | 
| if (data != null) { | 
| -        _socket.writeBytes(data); | 
| +        _socket.add(data); | 
| } | 
| } catch (_) { | 
| // The socket can be closed before _socket.done have a chance | 
|  |