Support canceling an incoming message, while the other end will be notified (by write-error from th…

sdk/lib/io/http_parser.dart

Index: sdk/lib/io/http_parser.dart
diff --git a/sdk/lib/io/http_parser.dart b/sdk/lib/io/http_parser.dart
index d3a7e76261f10559f3b13cc876af4fa0bd20e188..68fbc324ab643af712ada50b8ab1c53930dd198b 100644
--- a/sdk/lib/io/http_parser.dart
+++ b/sdk/lib/io/http_parser.dart
@@ -874,7 +874,7 @@ class _HttpParser
     assert(_incoming == null);
     assert(_bodyController == null);
     _bodyController = new StreamController<List<int>>(
-        onSubscriptionStateChange: _updateParsePauseState,
+        onSubscriptionStateChange: _bodySubscriptionStateChange,
         onPauseStateChange: _updateParsePauseState);
     _incoming = new _HttpIncoming(
         _headers, transferLength, _bodyController.stream);
@@ -902,6 +902,14 @@ class _HttpParser
     _paused = true;
   }
 
+  void _bodySubscriptionStateChange() {
+    if (_incoming != null && !_bodyController.hasSubscribers) {
+      _closeIncoming();
+    } else {
+      _updateParsePauseState();
+    }
+  }
+
   void _updateParsePauseState() {
     if (_bodyController != null) {
       if (_bodyController.hasSubscribers && !_bodyController.isPaused) {