[Blink-in-JS] Migrate the PrivateScript specific methods/attributes to ScriptController

Source/core/testing/PartialPrivateScriptTest.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(PrivateScriptTestPrototype) {
+privateScriptController.installClass("PrivateScriptTest", function(PrivateScriptTestPrototype) {
 
     PrivateScriptTestPrototype.addIntegerInPartial = function(value1, value2) {
         return value1 + value2;
     }
 
     PrivateScriptTestPrototype.addInteger2InPartial = function(value1, value2) {
         // addValue_ is a method defined in PrivateScriptTest.js.
         // Partial interfaces should be able to use methods defined in the base interface.
         return this.addValues_(value1, value2);
     }
 
     Object.defineProperty(PrivateScriptTestPrototype, "stringAttributeInPartial", {
         get: function() { return this.m_stringAttributeInPartial; },
         set: function(value) { this.m_stringAttributeInPartial = value; }
     });
 
 });