Stop treating StreamController as a Stream.

pkg/http/test/mock_client_test.dart

Index: pkg/http/test/mock_client_test.dart
diff --git a/pkg/http/test/mock_client_test.dart b/pkg/http/test/mock_client_test.dart
index 6467351a2057e332e71e2ea897e4b6f63bcc1588..1ffc373ee75069302dc5f834edc1b2406a86c804 100644
--- a/pkg/http/test/mock_client_test.dart
+++ b/pkg/http/test/mock_client_test.dart
@@ -35,13 +35,13 @@ void main() {
   test('handles a streamed request', () {
     var client = new MockClient.streaming((request, bodyStream) {
       return bodyStream.bytesToString().then((bodyString) {
-        var stream = new StreamController<List<int>>();
+        var controller = new StreamController<List<int>>();
         async.then((_) {
-          stream.add('Request body was "$bodyString"'.charCodes);
-          stream.close();
+          controller.add('Request body was "$bodyString"'.charCodes);
+          controller.close();
         });
 
-        return new http.StreamedResponse(stream, 200, -1);
+        return new http.StreamedResponse(controller.stream, 200, -1);
       });
     });