Format all tests.

tests/language/mixin_type_parameters_simple_test.dart

Index: tests/language/mixin_type_parameters_simple_test.dart
diff --git a/tests/language/mixin_type_parameters_simple_test.dart b/tests/language/mixin_type_parameters_simple_test.dart
index c077cabaeedccafbf82d5dd32a277595b5a74875..b8ab415bf408480efa474fe792445fc4fe7ec5ee 100644
--- a/tests/language/mixin_type_parameters_simple_test.dart
+++ b/tests/language/mixin_type_parameters_simple_test.dart
@@ -14,7 +14,7 @@ class M2<Y> {
   m2() => Y;
 }
 
-class A<T> extends S with M1<T> , M2<T> { }
+class A<T> extends S with M1<T>, M2<T> {}
 
 main() {
   var a = new A<int>();