Address review comments from: https://chromiumcodereview.appspot.com/9750003.

frog/tests/native/src/NativeNoSuchMethodException2FrogTest.dart

Index: frog/tests/native/src/NativeNoSuchMethodException2FrogTest.dart
===================================================================
--- frog/tests/native/src/NativeNoSuchMethodException2FrogTest.dart	(revision 5968)
+++ frog/tests/native/src/NativeNoSuchMethodException2FrogTest.dart	(working copy)
@@ -3,24 +3,37 @@
 // BSD-style license that can be found in the LICENSE file.
 
 class A native "*A" {
-  bar() => 42;
 }
 
-class B native "*B" {
-  foo() => 42;
+class B extends A native "*B" {
+  foo() native;
 }
 
 makeA() native;
+makeB() native;
 
 setup() native """
+function inherits(child, parent) {
+  if (child.prototype.__proto__) {
+    child.prototype.__proto__ = parent.prototype;
+  } else {
+    function tmp() {};
+    tmp.prototype = parent.prototype;
+    child.prototype = new tmp();
+    child.prototype.constructor = child;
+  }
+}
   function A() {}
+  function B() {}
+  inherits(B, A);
   makeA = function() { return new A; }
+  makeB = function() { return new B; }
+  B.prototype.foo = function() { return 42; }
 """;
 
 main() {
   setup();
   var a = makeA();
-  a.bar();
   var exception;
   try {
     a.foo();
@@ -28,4 +41,7 @@
     exception = e;
   }
   Expect.isNotNull(exception);
+
+  var b = makeB();
+  Expect.equals(42, b.foo());
 }