Format all tests.

tests/language/mixin_super_constructor_multiple_test.dart

Index: tests/language/mixin_super_constructor_multiple_test.dart
diff --git a/tests/language/mixin_super_constructor_multiple_test.dart b/tests/language/mixin_super_constructor_multiple_test.dart
index 9e40a249d2f91cededa1d70bbab6f5dfd6ca5510..5201be3ddf832df20ae1556050f5a1b1700947fb 100644
--- a/tests/language/mixin_super_constructor_multiple_test.dart
+++ b/tests/language/mixin_super_constructor_multiple_test.dart
@@ -9,9 +9,9 @@ class S {
   S.foo() : i = 1742;
 }
 
-class M1 { }
+class M1 {}
 
-class M2 { }
+class M2 {}
 
 class C extends S with M1, M2 {
   C.foo() : super.foo();