dart2js: run dartfmt on tests

tests/compiler/dart2js/interpolation_folding_test.dart

 // Copyright (c) 2013, 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 'dart:async';
 import 'package:async_helper/async_helper.dart';
 import 'package:expect/expect.dart';
 import 'compiler_helper.dart';
 
 // Tests for
@@ skipping 28 matching lines @@
 """;
 
 main() {
   Future check(String test, String contained) {
     return compile(test, entry: 'foo').then((String generated) {
       Expect.isTrue(generated.contains(contained), contained);
     });
   }
 
   asyncTest(() => Future.wait([
-    // Full substitution.
-    check(TEST_1, r'"u120vhellow"'),
+        // Full substitution.
+        check(TEST_1, r'"u120vhellow"'),
 
-    // Adjacent string fragments get merged.
-    check(TEST_2, r'"xxxxxyyyyy"'),
+        // Adjacent string fragments get merged.
+        check(TEST_2, r'"xxxxxyyyyy"'),
 
-    // 1. No merging of fragments that are multi-use.  Prevents exponential code
-    //    and keeps author's manual CSE.
-    // 2. Know string values require no stringification.
-    check(TEST_3, r'return b + "x" + b'),
+        // 1. No merging of fragments that are multi-use.  Prevents exponential code
+        //    and keeps author's manual CSE.
+        // 2. Know string values require no stringification.
+        check(TEST_3, r'return b + "x" + b'),
 
-    // Known int value can be formatted directly.
-    check(TEST_4, r'return "" + b.length'),
-  ]));
+        // Known int value can be formatted directly.
+        check(TEST_4, r'return "" + b.length'),
+      ]));
 }