bindings: Fixes layouttests when moving attributes to prototype chains.

LayoutTests/fast/js/script-tests/delete-syntax.js

 description(
 "This test checks whether various forms of delete expression are allowed."
 );
 
 window.y = 0;
 
 shouldBeTrue('delete x');
 window.x = 0;
 window.y = 0;
 shouldBeTrue('delete window.x');
@@ skipping 55 matching lines @@
 // Reverse order of delete & overwrite, tests delete after preventExtensions.
 shouldBe("RegExp.prototype.compile", "regExpPrototypeCompile");
 shouldBe("RegExp.prototype.exec", "undefined");
 shouldBe("RegExp.prototype.test", "null");
 
 // Check that once a property is deleted its name is removed from the property name array.
 delete Object.prototype.__defineSetter__;
 shouldBe("Object.getOwnPropertyNames(Object.prototype).indexOf('__defineSetter__')", "-1");
 
 delete navigator.appCodeName;
-var navigatorPropertyNames = Object.getOwnPropertyNames(navigator);
+delete Navigator.prototype.appCodeName;
+var navigatorPropertyNames = [];
+for (var property in navigator) {
+    navigatorPropertyNames.push(property);
+}
 var expectedPropertyNames = [
     "appName",
     "appVersion",
     "language",
     "userAgent",
     "platform",
     "plugins",
     "mimeTypes",
     "product",
     "productSub",
     "vendor",
     "vendorSub",
     "cookieEnabled",
     "onLine"
 ];
 
 for (var i = 0; i < expectedPropertyNames.length; ++i)
     shouldBeTrue("navigatorPropertyNames.indexOf('" + expectedPropertyNames[i] +"') != -1");