Make the HTTP server close non-persistent connections

tests/standalone/io/http_connection_close_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:isolate");
+#import("dart:io");
+
+void testHttp10Close() {
+  HttpServer server = new HttpServer();
+  server.listen("127.0.0.1", 0, 5);
+
+  Socket socket = new Socket("127.0.0.1", server.port);
+  socket.onConnect = () {
+    List<int> buffer = new List<int>(1024);
+    socket.outputStream.writeString("GET / HTTP/1.0\r\n\r\n");
+    socket.onData = () => socket.readList(buffer, 0, buffer.length);
+    socket.onClosed = () {
+      socket.close(true);
+      server.close();
+    };
+  };
+}
+
+void testHttp11Close() {
+  HttpServer server = new HttpServer();
+  server.listen("127.0.0.1", 0, 5);
+
+  Socket socket = new Socket("127.0.0.1", server.port);
+  socket.onConnect = () {
+    List<int> buffer = new List<int>(1024);
+    socket.outputStream.writeString(
+        "GET / HTTP/1.1\r\nConnection: close\r\n\r\n");
+    socket.onData = () => socket.readList(buffer, 0, buffer.length);
+    socket.onClosed = () {
+      socket.close(true);
+      server.close();
+    };
+  };
+}
+
+main() {
+  testHttp10Close();
+  testHttp11Close();
+}