Finish strong mode cleaning of dart2js.

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

Index: pkg/compiler/lib/src/js_emitter/class_stub_generator.dart
diff --git a/pkg/compiler/lib/src/js_emitter/class_stub_generator.dart b/pkg/compiler/lib/src/js_emitter/class_stub_generator.dart
index 1b087c5db72a1df7f0b44bbbb2300bca3f618217..1441f9aa82b33f5d2f7923f624efdb3e9f27d1cb 100644
--- a/pkg/compiler/lib/src/js_emitter/class_stub_generator.dart
+++ b/pkg/compiler/lib/src/js_emitter/class_stub_generator.dart
@@ -44,9 +44,9 @@ class ClassStubGenerator {
     //            fields.map(
     //                (name) => js('this.# = #', [name, name]))]));
     var typeParameters = const <jsAst.Parameter>[];
-    var typeInits = const <jsAst.Expression>[];
+    dynamic typeInits = const <jsAst.Expression>[];
     if (hasRtiField) {
-      var rtiName = _namer.rtiFieldJsName;
+      dynamic rtiName = _namer.rtiFieldJsName;
       typeParameters = rtiName;
       typeInits = js('this.# = #', [rtiName, rtiName]);
     }