Revert "Add native_testing library to mock @Native classes"

tests/compiler/dart2js_native/native_method_rename2_frog_test.dart

Index: tests/compiler/dart2js_native/native_method_rename2_frog_test.dart
diff --git a/tests/compiler/dart2js_native/native_method_rename2_frog_test.dart b/tests/compiler/dart2js_native/native_method_rename2_frog_test.dart
index 5979e1e5ff808151a1ae7b28c3ed7b02944efad9..e375f2ff0d791d8b014d7f48b8d6d134d0abdb62 100644
--- a/tests/compiler/dart2js_native/native_method_rename2_frog_test.dart
+++ b/tests/compiler/dart2js_native/native_method_rename2_frog_test.dart
@@ -4,7 +4,8 @@
 
 // Test the feature where the native string declares the native method's name.
 
-import "native_testing.dart";
+import "package:expect/expect.dart";
+import 'dart:_js_helper' show Native, JSName;
 
 @Native("A")
 class A {
@@ -41,9 +42,6 @@ B.prototype.fooB = function(){return 200;};
 
 makeA = function(){return new A};
 makeB = function(){return new B};
-
-self.nativeConstructor(A);
-self.nativeConstructor(B);
 """;
 
 testDynamic() {
@@ -78,7 +76,6 @@ testTyped() {
 }
 
 main() {
-  nativeTesting();
   setup();
 
   testDynamic();