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

Source/core/dom/Element.idl

 /*
  * Copyright (C) 2006, 2007, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 14 matching lines @@
     // DOM Level 1 Core
 
     [TreatReturnedNullStringAs=Null, PerWorldBindings] readonly attribute DOMString tagName;
 
     [TreatReturnedNullStringAs=Null] DOMString getAttribute(DOMString name);
     [RaisesException, CustomElementCallbacks] void setAttribute(DOMString name, DOMString value);
     [CustomElementCallbacks] void removeAttribute(DOMString name);
     [MeasureAs=ElementGetAttributeNode] Attr getAttributeNode([Default=Undefined] optional DOMString name); // Removed from DOM4.
     [RaisesException, CustomElementCallbacks, MeasureAs=ElementSetAttributeNode] Attr setAttributeNode([Default=Undefined, StrictTypeChecking] optional Attr newAttr); // Removed from DOM4.
     [RaisesException, CustomElementCallbacks, MeasureAs=ElementRemoveAttributeNode] Attr removeAttributeNode([Default=Undefined, StrictTypeChecking] optional Attr oldAttr); // Removed from DOM4.
-    [PerWorldBindings] NodeList getElementsByTagName(DOMString name);
+    [PerWorldBindings] HTMLCollection getElementsByTagName(DOMString name);
 
     [PerWorldBindings] readonly attribute NamedNodeMap     attributes;
     [MeasureAs=HasAttributes] boolean hasAttributes();
 
     // DOM Level 2 Core
 
     DOMString getAttributeNS([TreatNullAs=NullString] DOMString namespaceURI, DOMString localName);
     [RaisesException, CustomElementCallbacks] void setAttributeNS([TreatNullAs=NullString] DOMString namespaceURI, DOMString qualifiedName, DOMString value);
     [CustomElementCallbacks] void removeAttributeNS([TreatNullAs=NullString] DOMString namespaceURI, DOMString localName);
-    NodeList getElementsByTagNameNS([TreatNullAs=NullString] DOMString namespaceURI, DOMString localName);
+    HTMLCollection getElementsByTagNameNS([TreatNullAs=NullString] DOMString namespaceURI, DOMString localName);
     [MeasureAs=ElementGetAttributeNodeNS] Attr getAttributeNodeNS([TreatNullAs=NullString,Default=Undefined] optional DOMString namespaceURI,
                                                                   [Default=Undefined] optional DOMString localName); // Removed from DOM4.
     [RaisesException, CustomElementCallbacks, MeasureAs=ElementSetAttributeNodeNS] Attr setAttributeNodeNS([Default=Undefined, StrictTypeChecking] optional Attr newAttr); // Removed from DOM4.
     boolean hasAttribute(DOMString name);
     boolean hasAttributeNS([TreatNullAs=NullString] DOMString namespaceURI, DOMString localName);
 
     [PerWorldBindings] readonly attribute CSSStyleDeclaration style;
 
     // DOM4
     [Reflect] attribute DOMString id;
@@ skipping 23 matching lines @@
     void blur();
     void scrollIntoView(optional boolean alignWithTop);
 
     // WebKit extensions
 
     void scrollIntoViewIfNeeded(optional boolean centerIfNeeded);
     void scrollByLines([Default=Undefined] optional long lines);
     void scrollByPages([Default=Undefined] optional long pages);
 
     // HTML 5
-    NodeList getElementsByClassName(DOMString classNames);
+    HTMLCollection getElementsByClassName(DOMString classNames);
     [TreatNullAs=NullString, CustomElementCallbacks, PerWorldBindings, ActivityLogging=SetterForIsolatedWorlds, RaisesException=Setter] attribute DOMString innerHTML;
     [TreatNullAs=NullString, CustomElementCallbacks, RaisesException=Setter] attribute DOMString outerHTML;
     [CustomElementCallbacks, RaisesException] void insertAdjacentHTML(DOMString where, DOMString html);
 
     [Reflect=class, PerWorldBindings] attribute DOMString className;
     [PerWorldBindings] readonly attribute DOMTokenList classList;
 
     [PerWorldBindings] readonly attribute DOMStringMap dataset;
 
     // NodeSelector - Selector API
@@ skipping 42 matching lines @@
     [RuntimeEnabled=Touch] attribute EventHandler ontouchend;
     [RuntimeEnabled=Touch] attribute EventHandler ontouchmove;
     [RuntimeEnabled=Touch] attribute EventHandler ontouchstart;
     attribute EventHandler onwebkitfullscreenchange;
     attribute EventHandler onwebkitfullscreenerror;
     [PerWorldBindings, ActivityLogging=SetterForIsolatedWorlds] attribute EventHandler onwheel;
 };
 
 Element implements ParentNode;
 Element implements ChildNode;