Make StreamSubscription be the active part of a stream.

runtime/bin/socket_patch.dart

 // Copyright (c) 2013, 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.
 
 patch class RawServerSocket  {
   /* patch */ static Future<RawServerSocket> bind(address,
                                                   int port,
                                                   {int backlog: 0,
                                                    bool v6Only: false}) {
     return _RawServerSocket.bind(address, port, backlog, v6Only);
@@ skipping 824 matching lines @@
   }
 
   void write() {
     try {
       if (subscription == null) return;
       assert(buffer != null);
       // Write as much as possible.
       offset += socket._write(buffer, offset, buffer.length - offset);
       if (offset < buffer.length) {
         if (!paused) {
-          paused = true;
-          // TODO(ajohnsen): It would be nice to avoid this check.
-          // Some info: socket._write can emit an event, if it fails to write.
-          // If the user closes the socket in that event, stop() will be called
-          // before we get a change to pause.
-          if (subscription == null) return;
           subscription.pause();
         }
         socket._enableWriteEvent();
       } else {
         buffer = null;
         if (paused) {
           paused = false;
           subscription.resume();
         }
       }
@@ skipping 233 matching lines @@
     _raw.onBadCertificate = callback;
   }
 
   X509Certificate get peerCertificate {
     if (_raw == null) {
      throw new StateError("peerCertificate called on destroyed SecureSocket");
     }
     return _raw.peerCertificate;
   }
 }