Try to send EndStreamFlag together with headers (if possible)

lib/src/streams/stream_handler.dart

Index: lib/src/streams/stream_handler.dart
diff --git a/lib/src/streams/stream_handler.dart b/lib/src/streams/stream_handler.dart
index 3cdec55bd6ef436de2dc7c7648adf97d61165639..5a78aaa4d5ad799c5093bd316166e81ff620536e 100644
--- a/lib/src/streams/stream_handler.dart
+++ b/lib/src/streams/stream_handler.dart
@@ -197,10 +197,7 @@ class StreamHandler extends Object with TerminatableMixin, ClosableMixin {
   TransportStream newStream(List<Header> headers, {bool endStream: false}) {
     return ensureNotTerminatedSync(() {
       var stream = newLocalStream();
-      _sendHeaders(stream, headers);
-      if (endStream) {
-        _handleOutgoingClose(stream);
-      }
+      _sendHeaders(stream, headers, endStream: endStream);
       return stream;
     });
   }