Blink-in-JS: Implement internal APIs exposed only to private scripts

Source/core/testing/PrivateScriptTest.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 "use strict";
 
 installClass("PrivateScriptTest", function(global) {
     var InternalsPrototype = Object.create(Element.prototype);
 
     InternalsPrototype.initialize = function() {
@@ skipping 111 matching lines @@
 
     InternalsPrototype.addIntegerForPrivateScriptOnly = function(value1, value2) {
         return value1 + value2;
     }
 
     Object.defineProperty(InternalsPrototype, "stringAttributeForPrivateScriptOnly", {
         get: function() { return this.m_stringAttributeForPrivateScriptOnly; },
         set: function(value) { this.m_stringAttributeForPrivateScriptOnly = value; }
     });
 
+    InternalsPrototype.addIntegerImplementedInCPP = function(value1, value2) {
+        return this.addIntegerImplementedInCPPForPrivateScriptOnly(value1, value2);
+    }
+
+    Object.defineProperty(InternalsPrototype, "stringAttributeImplementedInCPP", {
+        get: function() { return this.m_stringAttributeImplementedInCPPForPrivateScriptOnly; },
+        set: function(value) { this.m_stringAttributeImplementedInCPPForPrivateScriptOnly = value; }
+    });
+
     return InternalsPrototype;
 });