Have getElementsByClassName() / getElementsByTagName*() return an HTMLCollection

LayoutTests/fast/dom/script-tests/domListEnumeration.js

 description(
 'This tests enumerating the elements of DOM lists.'
 );
 
 if (window.testRunner)
     testRunner.dumpAsText();
 
 // Create a testing environment that can be cleanup up easily.
 var testingGround = document.createElement('div');
 document.body.appendChild(testingGround);
@@ skipping 76 matching lines @@
 // HTMLSelectElement
 
 // ** Firefox DOESN'T include the indexGetter results in enumeration **
 // Window
 
 setup();
 
 var resultArray = new Array();
 
 // NodeList
-var nodeList = document.getElementsByTagName('ol');
+var nodeList = document.querySelectorAll('ol');
 resultArray = iterateList(nodeList);
 
 shouldBe("resultArray.length", "5");
 shouldBe("resultArray[0].i", "'0'");
 shouldBe("resultArray[0].item", "nodeList.item(0)");
 shouldBe("resultArray[1].i", "'1'");
 shouldBe("resultArray[1].item", "nodeList.item(1)");
 shouldBe("resultArray[2].i", "'2'");
 shouldBe("resultArray[2].item", "nodeList.item(2)");
 
@@ skipping 88 matching lines @@
 shouldBe("resultArray[0].i", "'0'");
 shouldBe("resultArray[0].item", "mediaList.item(0)");
 shouldBe("resultArray[1].i", "'1'");
 shouldBe("resultArray[1].item", "mediaList.item(1)");
 shouldBe("resultArray[2].i", "'2'");
 shouldBe("resultArray[2].item", "mediaList.item(2)");
 
 debug("");
 
 document.body.removeChild(testingGround);