Format all tests.

tests/language/mixin_lib_extends_field_test.dart

Index: tests/language/mixin_lib_extends_field_test.dart
diff --git a/tests/language/mixin_lib_extends_field_test.dart b/tests/language/mixin_lib_extends_field_test.dart
index 5edafd3d5ac49f42b2ccaa2c6bb5dcdc7e9ead90..b54433e1aab4cff3bc83d300652570360b085a03 100644
--- a/tests/language/mixin_lib_extends_field_test.dart
+++ b/tests/language/mixin_lib_extends_field_test.dart
@@ -11,9 +11,11 @@ class S {
   var foo = "S-foo";
 }
 
-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 {
   var fez = "F-fez";