Use entities in class_stub_generator.

pkg/compiler/lib/src/js_emitter/main_call_stub_generator.dart

Index: pkg/compiler/lib/src/js_emitter/main_call_stub_generator.dart
diff --git a/pkg/compiler/lib/src/js_emitter/main_call_stub_generator.dart b/pkg/compiler/lib/src/js_emitter/main_call_stub_generator.dart
index 36a305cf9affbb4f9ca5359de683dff6815cb9d2..78a9515acbe11b409f1e4a8df816396f123a1f5b 100644
--- a/pkg/compiler/lib/src/js_emitter/main_call_stub_generator.dart
+++ b/pkg/compiler/lib/src/js_emitter/main_call_stub_generator.dart
@@ -7,15 +7,11 @@ library dart2js.js_emitter.main_call_stub_generator;
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
 
 import '../compiler.dart' show Compiler;
-import '../elements/elements.dart'
-    show
-    Element;
+import '../elements/elements.dart' show Element;
 import '../js/js.dart' as jsAst;
 import '../js/js.dart' show js;
 import '../js_backend/backend_helpers.dart' show BackendHelpers;
-import '../js_backend/js_backend.dart'
-    show
-    JavaScriptBackend;
+import '../js_backend/js_backend.dart' show JavaScriptBackend;
 
 import 'code_emitter_task.dart' show CodeEmitterTask;