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

Source/core/testing/PrivateScriptTest.js

Index: Source/core/testing/PrivateScriptTest.js
diff --git a/Source/core/testing/PrivateScriptTest.js b/Source/core/testing/PrivateScriptTest.js
index 88050ca7b3f59b7759a76dfd6b016427f2edee13..c6bb4550b91f4efe7bbde912e0ca2fa552e122f2 100644
--- a/Source/core/testing/PrivateScriptTest.js
+++ b/Source/core/testing/PrivateScriptTest.js
@@ -129,5 +129,14 @@ installClass("PrivateScriptTest", function(global) {
         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;
 });