Avoid duplicated imports.

dart/tests/compiler/dart2js/backend_htype_list_test.dart

Index: dart/tests/compiler/dart2js/backend_htype_list_test.dart
diff --git a/dart/tests/compiler/dart2js/backend_htype_list_test.dart b/dart/tests/compiler/dart2js/backend_htype_list_test.dart
index 5d56b84bd4d65004a913d7b6ab3898f9d50b8b39..30369be8d2bf77a46d3612f35eb2c474cc7c2a3a 100644
--- a/dart/tests/compiler/dart2js/backend_htype_list_test.dart
+++ b/dart/tests/compiler/dart2js/backend_htype_list_test.dart
@@ -2,12 +2,12 @@
 // 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:uri";
+import 'dart:uri';
 
-import "../../../lib/compiler/implementation/elements/elements.dart";
-import "../../../lib/compiler/implementation/js_backend/js_backend.dart";
-import "../../../lib/compiler/implementation/ssa/ssa.dart";
-import "../../../lib/compiler/implementation/dart2jslib.dart";
+import '../../../lib/compiler/implementation/elements/elements.dart';
+import '../../../lib/compiler/implementation/js_backend/js_backend.dart';
+import '../../../lib/compiler/implementation/ssa/ssa.dart';
+import '../../../lib/compiler/implementation/dart2jslib.dart' show Selector;
 
 import 'compiler_helper.dart';
 import 'parser_helper.dart';