Make event-handlers edge-triggered and move socket-state to Dart.

tests/standalone/io/http_no_reason_phrase_test.dart

 // (c) 2014, 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.
 
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
 import "package:expect/expect.dart";
 import "dart:async";
 import "dart:isolate";
 import "dart:io";
 
 // Test that a response line without any reason phrase is handled.
 void missingReasonPhrase(int statusCode, bool includeSpace) {
   var client = new HttpClient();
   ServerSocket.bind("127.0.0.1", 0).then((server) {
      server.listen((client) {
+        client.listen(null);
         if (includeSpace) {
           client.write("HTTP/1.1 $statusCode \r\n\r\n");
         } else {
           client.write("HTTP/1.1 $statusCode\r\n\r\n");
         }
         client.close();
       });
       client.getUrl(Uri.parse("http://127.0.0.1:${server.port}/"))
         .then((request) => request.close())
         .then((response) {
           Expect.equals(statusCode, response.statusCode);
           Expect.equals("", response.reasonPhrase);
+          return response.drain();
         })
         .whenComplete(() => server.close());
   });
 }
 
 void main() {
   missingReasonPhrase(HttpStatus.OK, true);
   missingReasonPhrase(HttpStatus.INTERNAL_SERVER_ERROR, true);
   missingReasonPhrase(HttpStatus.OK, false);
   missingReasonPhrase(HttpStatus.INTERNAL_SERVER_ERROR, false);
 }