Make pkg/http use HttpClient.shutdown(force: true).

pkg/http/lib/src/base_request.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.
 
 library base_request;
 
 import 'dart:io';
+import 'dart:isolate';
 import 'dart:uri';
 
 import 'client.dart';
 import 'streamed_response.dart';
 
 /// The base class for HTTP requests.
 ///
 /// Subclasses of [BaseRequest] can be constructed manually and passed to
 /// [BaseClient.send], which allows the user to provide fine-grained control
 /// over the request properties. However, usually it's easier to use convenience
@@ skipping 79 matching lines @@
   }
 
   /// Sends this request.
   ///
   /// This automatically initializes a new [Client] and closes that client once
   /// the request is complete. If you're planning on making multiple requests to
   /// the same server, you should use a single [Client] for all of those
   /// requests.
   Future<StreamedResponse> send() {
     var client = new Client();
-    var future = client.send(this);
-    future.onComplete((_) => client.close());
-    return future;
+    return client.send(this).transform((response) {
+      // TODO(nweiz): This makes me sick to my stomach, but it's currently the
+      // best way to listen for the response stream being closed. Kill it with
+      // fire once issue 4202 is fixed.
+      new Timer.repeating(100, (timer) {
+        if (response.stream.closed) {
+          client.close();
+          timer.cancel();
+        }
+      });
+
+      return response;
+    });
   }
 
   /// Throws an error if this request has been finalized.
   void _checkFinalized() {
     if (!finalized) return;
     throw new StateError("Can't modify a finalized Request.");
   }
 }