Replace Backend with JavaScriptBackend.

tests/compiler/dart2js/kernel/getters_setters_test.dart

 // Copyright (c) 2016, 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.
 
 import 'package:test/test.dart';
 
 import 'helper.dart' show check;
 
 main() {
   group('compile getters with kernel', () {
@@ skipping 39 matching lines @@
 
 class B extends A {
 
   int get rotations => super.nothing * 3;
 }
 
 main() => new B().foo;
 ''';
       return check(code);
     });
-
   });
 
   group('compile setters with kernel', () {
     test('top-level', () {
       String code = '''
 set foo(int newFoo) {
   // do nothing
 }
 main() {
   foo = 1;
 }''';
       return check(code);
     });
 
     test('static', () {
       String code = '''
 class A {
   static set foo(int newFoo) {
     // do nothing
   }
 }
 main() {
   A.foo = 1;
 }
 ''';
       return check(code);
     });
   });
 
-    test('super set', () {
-      String code = '''
+  test('super set', () {
+    String code = '''
 class A {
   set ferocious(int newFerocious) {}
 }
 
 class B extends A {
   bar() {
     super.ferocious = 87;
   }
 }
 main() {
   new B().bar();
 }''';
-      return check(code);
-    });
+    return check(code);
+  });
 
-    test('super set no such method', () {
-      String code = '''
+  test('super set no such method', () {
+    String code = '''
 class A {
   final ferocious = 0;
   noSuchMethod(_) => 42;
 }
 
 class B extends A {
   bar() {
     super.ferocious = 87;
   }
 }
 main() {
   new B().bar();
 }''';
-      return check(code);
-    });
+    return check(code);
+  });
 }