dart2js: run dartfmt on tests

tests/compiler/dart2js/deferred_custom_element_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.
 
 // Test of the graph segmentation algorithm used by deferred loading
 // to determine which elements can be deferred and which libraries
 // much be included in the initial download (loaded eagerly).
 
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/compiler.dart';
@@ skipping 13 matching lines @@
     var foo = lib.find("foo");
     Expect.notEquals(mainOutputUnit, outputUnitForElement(foo));
     // Native elements are not deferred
     Expect.equals(mainOutputUnit, outputUnitForElement(customType));
   });
 }
 
 // The main library imports a file defining a custom element.
 // Registering this class implicitly causes the constructors to be
 // live. Check that this is handled.
-const Map MEMORY_SOURCE_FILES = const {"main.dart": """
+const Map MEMORY_SOURCE_FILES = const {
+  "main.dart": """
 import "lib.dart" deferred as a;
 import 'dart:html';
 
 main() {
   document.registerElement("foo-tag", a.a);
   a.foo();
 }
-""", "lib.dart": """
+""",
+  "lib.dart": """
 import 'dart:html';
 var a = CustomType;
 
 class CustomType extends HtmlElement {
   factory CustomType() => null;
   CustomType.created() : super.created() ;
 }
 
 foo() {}
-""",};
+""",
+};