Format all tests.

tests/language_strong/mixin_regress_13688_test.dart

Index: tests/language_strong/mixin_regress_13688_test.dart
diff --git a/tests/language_strong/mixin_regress_13688_test.dart b/tests/language_strong/mixin_regress_13688_test.dart
index 00115394e45d789a6a68ddf8add312fd13682f42..0c01537298eb0f47a0c4700e5ab26069afe8bf92 100644
--- a/tests/language_strong/mixin_regress_13688_test.dart
+++ b/tests/language_strong/mixin_regress_13688_test.dart
@@ -10,7 +10,7 @@ class ComparableMixin<E> {
   }
 }
 
-class KUID extends Object with ComparableMixin<KUID> { }
+class KUID extends Object with ComparableMixin<KUID> {}
 
 main() {
   var kuid = new KUID();