Revert "Add native_testing library to mock @Native classes"

tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart

Index: tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart
diff --git a/tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart b/tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart
index 1d3cdcc1bd87eb4ae51443753a31e110e05f2aad..cb093cb6ae199e414483e8aceeff4e99784be2cc 100644
--- a/tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart
+++ b/tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart
@@ -6,7 +6,8 @@
 // fields.  However, native fields keep their name.  The implication: a getter
 // for the field must be based on the field's name, not the field's jsname.
 
-import 'native_testing.dart';
+import "package:expect/expect.dart";
+import 'dart:_js_helper' show Native, JSName;
 
 abstract class I {
   int key;
@@ -46,15 +47,13 @@ X.prototype.key = function(){return 666;};
 
 makeA = function(){return new A};
 makeX = function(){return new X};
-
-self.nativeConstructor(A);
-self.nativeConstructor(X);
 """;
 
 testDynamic() {
-  var a = confuse(makeA());
-  var b = confuse(new B());
-  var x = confuse(makeX());
+  var things = [makeA(), new B(), makeX()];
+  var a = things[0];
+  var b = things[1];
+  var x = things[2];
 
   Expect.equals(111, a.key);
   Expect.equals(222, b.key);
@@ -92,7 +91,6 @@ testTyped() {
 }
 
 main() {
-  nativeTesting();
   setup();
 
   testTyped();