dart2js: run dartfmt on tests

tests/compiler/dart2js_native/downcast_test.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Test for downcasts on native classes.
 
 import "dart:_js_helper";
 import "package:expect/expect.dart";
 
-abstract class J {
-}
+abstract class J {}
 
 abstract class I extends J {
   I read();
   write(I x);
 }
 
 // Native implementation.
 
 @Native("A")
 class A implements I {
   // The native class accepts only other native instances.
-  A read() native;
-  write(A x) native;
+  A read() native ;
+  write(A x) native ;
 }
 
 @Native("B")
-class B extends A {
-}
+class B extends A {}
 
-makeA() native;
-makeB() native;
+makeA() native ;
+makeB() native ;
 
 void setup() native """
 // This code is all inside 'setup' and so not accesible from the global scope.
 function inherits(child, parent) {
   if (child.prototype.__proto__) {
     child.prototype.__proto__ = parent.prototype;
   } else {
     function tmp() {};
     tmp.prototype = parent.prototype;
     child.prototype = new tmp();
@@ skipping 31 matching lines @@
   Expect.equals(b1, b1 as I);
   Expect.equals(b1, b1 as A);
   Expect.equals(b1, b1 as B);
 
   Expect.equals(a1, a1 as J);
   Expect.equals(a1, a1 as I);
   Expect.equals(a1, a1 as A);
   Expect.throws(() => a1 as B);
   Expect.throws(() => a1 as C);
 }