Re-implement http sessions.

tests/standalone/io/http_session_test.dart

 // Copyright (c) 2012, 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.
 
 import 'dart:async';
 import 'dart:io';
 
 const SESSION_ID = "DARTSESSID";
 
 String getSessionId(List<Cookie> cookies) {
   var id = cookies.reduce(null, (last, cookie) {
     if (last != null) return last;
     if (cookie.name.toUpperCase() == SESSION_ID) {
       Expect.isTrue(cookie.httpOnly);
       return cookie.value;
     }
     return null;
   });
   Expect.isNotNull(id);
   return id;
 }
 
 Future<String> connectGetSession(int port, [String session]) {
-  var c = new Completer();
   var client = new HttpClient();
-  var conn = client.get("127.0.0.1", port, "/");
-  conn.onRequest = (request) {
-    if (session != null) {
-      request.cookies.add(new Cookie(SESSION_ID, session));
-    }
-    request.outputStream.close();
-  };
-  conn.onResponse = (response) {
-    response.inputStream.onData = response.inputStream.read;
-    response.inputStream.onClosed = () {
-      client.shutdown();
-      c.complete(getSessionId(response.cookies));
-    };
-  };
-  return c.future;
+  return client.get("127.0.0.1", port, "/")
+    .then((request) {
+      if (session != null) {
+        request.cookies.add(new Cookie(SESSION_ID, session));
+      }
+      return request.close();
+    })
+    .then((response) {
+      return response.reduce(getSessionId(response.cookies), (v, _) => v);
+    });
 }
 
 void testSessions(int sessionCount) {
-  HttpServer server = new HttpServer();
-  server.listen("127.0.0.1", 0);
+  HttpServer server = new HttpServer("127.0.0.1", 0);
   var sessions = new Set();
-  server.defaultRequestHandler = (request, response) {
+  server.listen((request) {
     sessions.add(request.session().id);
-    response.outputStream.close();
-  };
+    request.response.close();
+  });
 
   var futures = [];
   for (int i = 0; i < sessionCount; i++) {
     futures.add(connectGetSession(server.port).then((session) {
       Expect.isNotNull(session);
       Expect.isTrue(sessions.contains(session));
       return connectGetSession(server.port, session).then((session2) {
         Expect.equals(session2, session);
         Expect.isTrue(sessions.contains(session2));
         return session2;
         });
     }));
   }
   Futures.wait(futures).then((clientSessions) {
     Expect.equals(sessions.length, sessionCount);
     Expect.setEquals(new Set.from(clientSessions), sessions);
     server.close();
   });
 }
 
 void testTimeout(int sessionCount) {
-  HttpServer server = new HttpServer();
+  HttpServer server = new HttpServer("127.0.0.1", 0);
   server.sessionTimeout = 0;
-  server.listen("127.0.0.1", 0);
   var timeouts = [];
-  server.defaultRequestHandler = (request, response) {
+  server.listen((request) {
     var c = new Completer();
     timeouts.add(c.future);
     request.session().onTimeout = () {
       c.complete(null);
     };
-    response.outputStream.close();
-  };
+    request.response.close();
+  });
 
   var futures = [];
   for (int i = 0; i < sessionCount; i++) {
     futures.add(connectGetSession(server.port));
   }
   Futures.wait(futures).then((clientSessions) {
     Futures.wait(timeouts).then((_) {
       futures = [];
       for (var id in clientSessions) {
         futures.add(connectGetSession(server.port, id).then((session) {
           Expect.isNotNull(session);
           Expect.notEquals(id, session);
         }));
       }
       Futures.wait(futures).then((_) {
         server.close();
       });
     });
   });
 }
 
 void main() {
   testSessions(5);
   testTimeout(5);
 }