Improve WebSocket interface by making it implement StreamSink.

sdk/lib/io/websocket.dart

Index: sdk/lib/io/websocket.dart
diff --git a/sdk/lib/io/websocket.dart b/sdk/lib/io/websocket.dart
index 65249f13ad9a449ad9067f34cf34f9a515b34cde..088002037c28dae066ca54d3369ea516b8f653fe 100644
--- a/sdk/lib/io/websocket.dart
+++ b/sdk/lib/io/websocket.dart
@@ -80,7 +80,7 @@ abstract class WebSocketTransformer
  * messages received. A text message will be of type [:String:] and a
  * binary message will be of type [:List<int>:].
  */
-abstract class WebSocket implements Stream {
+abstract class WebSocket implements Stream, StreamSink {
   /**
    * Possible states of the connection.
    */
@@ -133,13 +133,13 @@ abstract class WebSocket implements Stream {
   /**
    * Closes the web socket connection.

[Søren Gjesse, 2013/04/16 12:41:31]

Please add documentation on the default values. It is possible to not have a
status code and the server will see that. Reason is ignored if there is no
status code. Should we fail in that case?

[Anders Johnsen, 2013/04/16 13:46:22]

Done.

    */
-  void close([int code, String reason]);
+  Future close([int code, String reason]);
 
   /**
    * Sends data on the web socket connection. The data in [data] must
    * be either a [:String:], or a [:List<int>:] holding bytes.
    */
-  void send(data);
+  void add(data);

[Søren Gjesse, 2013/04/16 12:41:31]

We should add addStream with some dartdoc here as well. It should briefly
explain how to get flow control using a StreamController.

How about addError? How will that work?

[Anders Johnsen, 2013/04/16 13:46:22]

addError will more or less just close the connection. No need to extra
information about that (same as on http/socket).

 }