Global constructors should be configurable and not enumerable

LayoutTests/fast/js/resources/getOwnPropertyDescriptor.js

 description("Test to ensure correct behaviour of Object.getOwnPropertyDescriptor");
 
 function descriptorShouldBe(object, property, expected) {
     var test = 'Object.getOwnPropertyDescriptor('+object+", "+property+')';
     if ("writable" in expected) {
       //  shouldBe(test+'.writable', '' + expected.writable);
         shouldBe(test+'.value', '' + expected.value);
         shouldBeFalse(test+".hasOwnProperty('get')");
         shouldBeFalse(test+".hasOwnProperty('set')");
     } else {
@@ skipping 25 matching lines @@
 descriptorShouldBe("/(a)*/g.exec('a')", "'length'", {writable: true, enumerable: false, configurable: false, value:2});
 descriptorShouldBe("function(){}", "'length'", {writable: false, enumerable: false, configurable: false, value:0});
 descriptorShouldBe("Math.sin", "'length'", {writable: false, enumerable: false, configurable: false, value:1});
 descriptorShouldBe("Math.sin", "'name'", {writable: false, enumerable: false, configurable: false, value:"'sin'"});
 var global = this;
 descriptorShouldBe("global", "'global'", {writable: true, enumerable: true, configurable: false, value:"global"});
 descriptorShouldBe("global", "'undefined'", {writable: false, enumerable: false, configurable: false, value:"undefined"});
 descriptorShouldBe("global", "'NaN'", {writable: false, enumerable: false, configurable: false, value:"NaN"});
 descriptorShouldBe("global", "'Infinity'", {writable: false, enumerable: false, configurable: false, value:"Infinity"});
 descriptorShouldBe("global", "'window'", {writable: false, enumerable: true, configurable: false, value:"global"});
-descriptorShouldBe("global", "'XMLHttpRequest'", {writable: true, enumerable: true, configurable: false, value:"XMLHttpRequest"});
+descriptorShouldBe("global", "'XMLHttpRequest'", {writable: true, enumerable: false, configurable: true, value:"XMLHttpRequest"});
 descriptorShouldBe("global", "'length'", {writable: true, enumerable: true, configurable: false, value:"global.length"});
 descriptorShouldBe("global", "0", {writable: true, enumerable: false, configurable: false, value:"global[0]"});
 descriptorShouldBe("document.getElementsByTagName('div')", "'length'", {writable: false, enumerable: true, configurable: false, value:"1"});
 descriptorShouldBe("document.getElementsByTagName('div')", "0", {writable: false, enumerable: true, configurable: false, value:"document.getElementsByTagName('div')[0]"});
 descriptorShouldBe("document.getElementsByClassName('pass')", "0", {writable: false, enumerable: true, configurable: false, value:"document.getElementsByClassName('pass')[0]"});
 descriptorShouldBe("document.getElementsByClassName('pass')", "'length'", {writable: false, enumerable: true, configurable: false, value:"document.getElementsByClassName('pass').length"});
 var canvas = document.createElement("canvas");
 var canvasPixelArray = canvas.getContext("2d").createImageData(10,10).data;
 descriptorShouldBe("canvasPixelArray", "'length'", {writable: false, enumerable: true, configurable: false, value:"canvasPixelArray.length"});
 descriptorShouldBe("canvasPixelArray", "0", {writable: true, enumerable: true, configurable: false, value:"canvasPixelArray[0]"});
@@ skipping 30 matching lines @@
     shouldBe('property', normalOrder[i++]);
 i = 0;
 for (var property in Object.getOwnPropertyDescriptor(objectWithGetter, "getter"))
     shouldBe('property', accessorOrder[i++]);
 i = 0;
 for (var property in Object.getOwnPropertyDescriptor(objectWithSetter, "setter"))
     shouldBe('property', accessorOrder[i++]);
 i = 0;
 for (var property in Object.getOwnPropertyDescriptor(objectWithAccessor, "accessor"))
     shouldBe('property', accessorOrder[i++]);