Excluding XHR test for responseType=blob from Safari

tests/html/xhr_test.dart

Index: tests/html/xhr_test.dart
diff --git a/tests/html/xhr_test.dart b/tests/html/xhr_test.dart
index 8276b49962f0e7ce900614b93a54561a414b4cca..6214581348fa2f52c81539eae33689163c6e5af5 100644
--- a/tests/html/xhr_test.dart
+++ b/tests/html/xhr_test.dart
@@ -154,6 +154,17 @@ main() {
       }
     });
 
+    test('HttpRequestProgressEvent', () {
+      var expectation = HttpRequestProgressEvent.supported ?
+          returnsNormally : throws;
+      expect(() {
+        var event = new Event.eventType('XMLHttpRequestProgressEvent', '');
+        expect(event is HttpRequestProgressEvent, isTrue);
+      }, expectation);
+    });
+  });
+
+  group('xhr_requestBlob', () {
     test('XHR.request responseType blob', () {
       if (ArrayBuffer.supported) {
         return HttpRequest.request(url, responseType: 'blob').then(
@@ -165,14 +176,5 @@ main() {
           });
       }
     });
-
-    test('HttpRequestProgressEvent', () {
-      var expectation = HttpRequestProgressEvent.supported ?
-          returnsNormally : throws;
-      expect(() {
-        var event = new Event.eventType('XMLHttpRequestProgressEvent', '');
-        expect(event is HttpRequestProgressEvent, isTrue);
-      }, expectation);
-    });
   });
 }