Switch from interfaces to abstract classes in dart:io.

runtime/bin/websocket.dart

Index: runtime/bin/websocket.dart
diff --git a/runtime/bin/websocket.dart b/runtime/bin/websocket.dart
index ef8876cafd4bdd3928642687a540514ebf409578..5b5b862dabe6addcbca90a6316a1f825b16a161a 100644
--- a/runtime/bin/websocket.dart
+++ b/runtime/bin/websocket.dart
@@ -5,7 +5,7 @@
 /**
  * Web socket status codes used when closing a web socket connection.
  */
-interface WebSocketStatus {
+abstract class WebSocketStatus {
   static const int NORMAL_CLOSURE = 1000;
   static const int GOING_AWAY = 1001;
   static const int PROTOCOL_ERROR = 1002;
@@ -38,8 +38,8 @@ interface WebSocketStatus {
  *
  * This handler strives to implement web sockets as specified by RFC6455.
  */
-interface WebSocketHandler default _WebSocketHandler {
-  WebSocketHandler();
+abstract class WebSocketHandler {
+  factory WebSocketHandler() => new _WebSocketHandler();
 
   /**
    * Request handler to be registered with the HTTP server.
@@ -57,7 +57,7 @@ interface WebSocketHandler default _WebSocketHandler {
 /**
  * Server web socket connection.
  */
-interface WebSocketConnection extends Hashable {
+abstract class WebSocketConnection implements Hashable {
   /**
    * Sets the callback to be called when a message have been
    * received. The type on [message] is either [:String:] or
@@ -96,14 +96,15 @@ interface WebSocketConnection extends Hashable {
 /**
  * Client web socket connection.
  */
-interface WebSocketClientConnection
-    extends Hashable default _WebSocketClientConnection {
+abstract class WebSocketClientConnection implements Hashable {
   /**
    * Creates a new web socket client connection based on a HTTP client
    * connection. The HTTP client connection must be freshly opened.
    */
-  WebSocketClientConnection(HttpClientConnection conn,
-                            [List<String> protocols]);
+  factory WebSocketClientConnection(HttpClientConnection conn,
+                                    [List<String> protocols]) {
+    return new _WebSocketClientConnection(conn, protocols);
+  }
 
   /**
    * Sets the callback to be called when the request object for the
@@ -166,15 +167,15 @@ interface WebSocketClientConnection
 
 
 /**
- * Base interface for the events generated by the W3C complient
- * browser API for web sockets.
+ * Base class for the events generated by the W3C complient browser
+ * API for web sockets.
  */
-interface Event { }
+abstract class Event { }
 
 /**
  * Event delivered when there is data on a web socket connection.
  */
-interface MessageEvent extends Event default _WebSocketMessageEvent {
+abstract class MessageEvent extends Event {
   /**
    * The type of [message] is either [:String:] or [:List<int>:]
    * depending on whether it is a text or binary message. If the
@@ -187,7 +188,7 @@ interface MessageEvent extends Event default _WebSocketMessageEvent {
 /**
  * Event delivered when a web socket connection is closed.
  */
-interface CloseEvent extends Event default _WebSocketCloseEvent {
+abstract class CloseEvent extends Event {
   /**
    * Returns whether the connection was closed cleanly or not.
    */
@@ -212,7 +213,7 @@ interface CloseEvent extends Event default _WebSocketCloseEvent {
  * with the W3C browser API for web sockets specified in
  * http://dev.w3.org/html5/websockets/.
  */
-interface WebSocket default _WebSocket {
+abstract class WebSocket {
   /**
    * Possible states of the connection.
    */
@@ -227,7 +228,7 @@ interface WebSocket default _WebSocket {
    * [:String:] or [:List<String>:] specifying the subprotocols the
    * client is willing to speak.
    */
-  WebSocket(String url, [protocols]);
+  factory WebSocket(String url, [protocols]) => new _WebSocket(url, protocols);
 
   /**
    * Returns the current state of the connection.