Format all tests.

tests/language/mixin_lib_extends_method_test.dart

Index: tests/language/mixin_lib_extends_method_test.dart
diff --git a/tests/language/mixin_lib_extends_method_test.dart b/tests/language/mixin_lib_extends_method_test.dart
index 25ade937f7ca92c67bca346e916d04d30f569b07..105ddd86628b90b0da9f123ffe818c0eb1fa4fbc 100644
--- a/tests/language/mixin_lib_extends_method_test.dart
+++ b/tests/language/mixin_lib_extends_method_test.dart
@@ -12,9 +12,11 @@ class S {
   baz() => "S-baz";
 }
 
-class C extends S with L.M1 { }
-class D extends S with L.M1, L.M2 { }
-class E extends S with L.M2, L.M1 { }
+class C extends S with L.M1 {}
+
+class D extends S with L.M1, L.M2 {}
+
+class E extends S with L.M2, L.M1 {}
 
 class F extends E {
   fez() => "F-fez";