Add native_testing library to mock @Native classes

tests/compiler/dart2js_native/browser_compat_2_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // 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:_js_helper";
-import "package:expect/expect.dart";
+import "native_testing.dart";
 
 // Test for dartNativeDispatchHooksTransformer
 //  - uncached, instance, leaf and interior caching modes.
 //  - composition of getTag.
 
 @Native("T1A")
 class T1A {
   foo() native ;
 }
 
@@ skipping 39 matching lines @@
 T1A.prototype.name = function() { return "A"; }
 T1B.prototype.name = function() { return "B"; }
 T1C.prototype.name = function() { return "C"; }
 T1D.prototype.name = function() { return "D"; }
 
 makeT1A = function(){return new T1A;};
 makeT1B = function(){return new T1B;};
 makeT1C = function(){return new T1C;};
 makeT1D = function(){return new T1D;};
 
+self.nativeConstructor(T1A);
+self.nativeConstructor(T1B);
+self.nativeConstructor(T1C);
+self.nativeConstructor(T1D);
+
 var getTagCount = 0;
 getTagCallCount = function() { return getTagCount; }
 clearTagCallCount = function() { getTagCount = 0; }
 
 function transformer1(hooks) {
   var getTag = hooks.getTag;
 
   function getTagNew(obj) {
     var tag = getTag(obj);
     // Dependency to test composition, rename T1D -> Dep -> -T1D.
@@ skipping 16 matching lines @@
     if (tag == "Dep") return "-T1D";  // Leaf cached on prototype
     return tag;
   }
 
   hooks.getTag = getTagNew;
 }
 
 dartNativeDispatchHooksTransformer = [transformer1, transformer2];
 ''';
 
-var inscrutable;
-
 main() {
+  nativeTesting();
   setup();
-  inscrutable = (x) => x;
 
   var t1a = makeT1A();
   var t1b = makeT1B();
   var t1c = makeT1C();
   var t1d = makeT1D();
 
   clearTagCallCount();
-  Expect.equals("aA", inscrutable(t1a).foo(), 't1a is T1A');
-  Expect.equals("bB", inscrutable(t1b).foo(), 't1b is T1B');
-  Expect.equals("cC", inscrutable(t1c).foo(), 't1c is T1C');
-  Expect.equals("dD", inscrutable(t1d).foo(), 't1d is T1D');
+  Expect.equals("aA", confuse(t1a).foo(), 't1a is T1A');
+  Expect.equals("bB", confuse(t1b).foo(), 't1b is T1B');
+  Expect.equals("cC", confuse(t1c).foo(), 't1c is T1C');
+  Expect.equals("dD", confuse(t1d).foo(), 't1d is T1D');
   Expect.equals(4, getTagCallCount(), '4 fresh instances / types');
 
   clearTagCallCount();
-  Expect.equals("aA", inscrutable(t1a).foo(), 't1a is T1A');
-  Expect.equals("bB", inscrutable(t1b).foo(), 't1b is T1B');
-  Expect.equals("cC", inscrutable(t1c).foo(), 't1c is T1C');
-  Expect.equals("dD", inscrutable(t1d).foo(), 't1d is T1D');
+  Expect.equals("aA", confuse(t1a).foo(), 't1a is T1A');
+  Expect.equals("bB", confuse(t1b).foo(), 't1b is T1B');
+  Expect.equals("cC", confuse(t1c).foo(), 't1c is T1C');
+  Expect.equals("dD", confuse(t1d).foo(), 't1d is T1D');
   Expect.equals(1, getTagCallCount(), '1 = 1 uncached + (3 cached)');
 
   t1a = makeT1A();
   t1b = makeT1B();
   t1c = makeT1C();
   t1d = makeT1D();
 
   clearTagCallCount();
-  Expect.equals("aA", inscrutable(t1a).foo(), 't1a is T1A');
-  Expect.equals("bB", inscrutable(t1b).foo(), 't1b is T1B');
-  Expect.equals("cC", inscrutable(t1c).foo(), 't1c is T1C');
-  Expect.equals("dD", inscrutable(t1d).foo(), 't1d is T1D');
+  Expect.equals("aA", confuse(t1a).foo(), 't1a is T1A');
+  Expect.equals("bB", confuse(t1b).foo(), 't1b is T1B');
+  Expect.equals("cC", confuse(t1c).foo(), 't1c is T1C');
+  Expect.equals("dD", confuse(t1d).foo(), 't1d is T1D');
   Expect.equals(2, getTagCallCount(),
       '2 = 1 fresh instance + 1 uncached (+ 2 proto cached)');
 
   clearTagCallCount();
-  Expect.equals("aA", inscrutable(t1a).foo(), 't1a is T1A');
-  Expect.equals("bB", inscrutable(t1b).foo(), 't1b is T1B');
-  Expect.equals("cC", inscrutable(t1c).foo(), 't1c is T1C');
-  Expect.equals("dD", inscrutable(t1d).foo(), 't1d is T1D');
+  Expect.equals("aA", confuse(t1a).foo(), 't1a is T1A');
+  Expect.equals("bB", confuse(t1b).foo(), 't1b is T1B');
+  Expect.equals("cC", confuse(t1c).foo(), 't1c is T1C');
+  Expect.equals("dD", confuse(t1d).foo(), 't1d is T1D');
   Expect.equals(1, getTagCallCount(),
       '1 = 2 proto cached + 1 instance cached + 1 uncached');
 }