--- a/dom/webidl/HTMLAnchorElement.webidl
+++ b/dom/webidl/HTMLAnchorElement.webidl
@@ -7,16 +7,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-a-element
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-a-element
+[HTMLConstructor]
 interface HTMLAnchorElement : HTMLElement {
            [SetterThrows]
            attribute DOMString target;
            [SetterThrows]
            attribute DOMString download;
            [SetterThrows]
            attribute DOMString ping;
            [SetterThrows]

--- a/dom/webidl/HTMLAreaElement.webidl
+++ b/dom/webidl/HTMLAreaElement.webidl
@@ -8,16 +8,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  &
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-area-element
+[HTMLConstructor]
 interface HTMLAreaElement : HTMLElement {
            [SetterThrows]
            attribute DOMString alt;
            [SetterThrows]
            attribute DOMString coords;
            [SetterThrows]
            attribute DOMString shape;
            [SetterThrows]

--- a/dom/webidl/HTMLAudioElement.webidl
+++ b/dom/webidl/HTMLAudioElement.webidl
@@ -6,11 +6,11 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-audio-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
-[NamedConstructor=Audio(optional DOMString src)]
+[HTMLConstructor, NamedConstructor=Audio(optional DOMString src)]
 interface HTMLAudioElement : HTMLMediaElement {};
 

--- a/dom/webidl/HTMLBRElement.webidl
+++ b/dom/webidl/HTMLBRElement.webidl
@@ -8,16 +8,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-br-element
+[HTMLConstructor]
 interface HTMLBRElement : HTMLElement {};
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
 partial interface HTMLBRElement {
              [SetterThrows]
              attribute DOMString clear;
 };
 

--- a/dom/webidl/HTMLBaseElement.webidl
+++ b/dom/webidl/HTMLBaseElement.webidl
@@ -7,15 +7,16 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-base-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-base-element
+[HTMLConstructor]
 interface HTMLBaseElement : HTMLElement {
            [SetterThrows, Pure]
            attribute DOMString href;
            [SetterThrows, Pure]
            attribute DOMString target;
 };
 

--- a/dom/webidl/HTMLBodyElement.webidl
+++ b/dom/webidl/HTMLBodyElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLBodyElement : HTMLElement {
 };
 
 partial interface HTMLBodyElement {
   [TreatNullAs=EmptyString, SetterThrows] attribute DOMString text;
   [TreatNullAs=EmptyString, SetterThrows] attribute DOMString link;
   [TreatNullAs=EmptyString, SetterThrows] attribute DOMString vLink;
   [TreatNullAs=EmptyString, SetterThrows] attribute DOMString aLink;

--- a/dom/webidl/HTMLButtonElement.webidl
+++ b/dom/webidl/HTMLButtonElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-button-element
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-button-element
+[HTMLConstructor]
 interface HTMLButtonElement : HTMLElement {
   [SetterThrows, Pure]
            attribute boolean autofocus;
   [SetterThrows, Pure]
            attribute boolean disabled;
   [Pure]
   readonly attribute HTMLFormElement? form;
   [SetterThrows, Pure]

--- a/dom/webidl/HTMLCanvasElement.webidl
+++ b/dom/webidl/HTMLCanvasElement.webidl
@@ -8,16 +8,17 @@
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 interface nsISupports;
 interface Variant;
 
+[HTMLConstructor]
 interface HTMLCanvasElement : HTMLElement {
   [Pure, SetterThrows]
            attribute unsigned long width;
   [Pure, SetterThrows]
            attribute unsigned long height;
 
   [Throws]
   nsISupports? getContext(DOMString contextId, optional any contextOptions = null);

--- a/dom/webidl/HTMLDListElement.webidl
+++ b/dom/webidl/HTMLDListElement.webidl
@@ -8,16 +8,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-dl-element
+[HTMLConstructor]
 interface HTMLDListElement : HTMLElement {
 };
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
 partial interface HTMLDListElement {
            [SetterThrows]
            attribute boolean compact;
 };

--- a/dom/webidl/HTMLDataElement.webidl
+++ b/dom/webidl/HTMLDataElement.webidl
@@ -2,12 +2,13 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  *
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/multipage/text-level-semantics.html#the-data-element
  */
 
+[HTMLConstructor]
 interface HTMLDataElement : HTMLElement {
            [SetterThrows]
            attribute DOMString value;
 };

--- a/dom/webidl/HTMLDataListElement.webidl
+++ b/dom/webidl/HTMLDataListElement.webidl
@@ -6,11 +6,12 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLDataListElement : HTMLElement {
   readonly attribute HTMLCollection options;
 };

--- a/dom/webidl/HTMLDetailsElement.webidl
+++ b/dom/webidl/HTMLDetailsElement.webidl
@@ -6,12 +6,13 @@
  * The origin of this IDL file is
  * https://html.spec.whatwg.org/multipage/forms.html#the-details-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLDetailsElement : HTMLElement {
   [SetterThrows]
   attribute boolean open;
 };

--- a/dom/webidl/HTMLDirectoryElement.webidl
+++ b/dom/webidl/HTMLDirectoryElement.webidl
@@ -7,13 +7,14 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
+[HTMLConstructor]
 interface HTMLDirectoryElement : HTMLElement {
            [SetterThrows, Pure]
            attribute boolean compact;
 };
 

--- a/dom/webidl/HTMLDivElement.webidl
+++ b/dom/webidl/HTMLDivElement.webidl
@@ -6,14 +6,15 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLDivElement : HTMLElement {};
 
 partial interface HTMLDivElement {
   [SetterThrows]
            attribute DOMString align;
 };

--- a/dom/webidl/HTMLElement.webidl
+++ b/dom/webidl/HTMLElement.webidl
@@ -7,16 +7,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/ and
  * http://dev.w3.org/csswg/cssom-view/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLElement : Element {
   // metadata attributes
            attribute DOMString title;
            attribute DOMString lang;
   //         attribute boolean translate;
   [SetterThrows, Pure]
            attribute DOMString dir;
   [Constant]

--- a/dom/webidl/HTMLEmbedElement.webidl
+++ b/dom/webidl/HTMLEmbedElement.webidl
@@ -8,17 +8,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#HTMLEmbedElement-partial
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-embed-element
-[NeedResolve]
+[HTMLConstructor, NeedResolve]
 interface HTMLEmbedElement : HTMLElement {
   [Pure, SetterThrows]
            attribute DOMString src;
   [Pure, SetterThrows]
            attribute DOMString type;
   [Pure, SetterThrows]
            attribute DOMString width;
   [Pure, SetterThrows]

--- a/dom/webidl/HTMLFieldSetElement.webidl
+++ b/dom/webidl/HTMLFieldSetElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-fieldset-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLFieldSetElement : HTMLElement {
   [SetterThrows]
            attribute boolean disabled;
   readonly attribute HTMLFormElement? form;
   [SetterThrows]
            attribute DOMString name;
 
   readonly attribute DOMString type;

--- a/dom/webidl/HTMLFontElement.webidl
+++ b/dom/webidl/HTMLFontElement.webidl
@@ -6,13 +6,14 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLFontElement : HTMLElement {
   [TreatNullAs=EmptyString, SetterThrows] attribute DOMString color;
   [SetterThrows]                          attribute DOMString face;
   [SetterThrows]                          attribute DOMString size;
 };

--- a/dom/webidl/HTMLFormElement.webidl
+++ b/dom/webidl/HTMLFormElement.webidl
@@ -6,17 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#htmlformelement
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
-[OverrideBuiltins, LegacyUnenumerableNamedProperties]
+[OverrideBuiltins, LegacyUnenumerableNamedProperties, HTMLConstructor]
 interface HTMLFormElement : HTMLElement {
            [Pure, SetterThrows]
            attribute DOMString acceptCharset;
            [Pure, SetterThrows]
            attribute DOMString action;
            [Pure, SetterThrows]
            attribute DOMString autocomplete;
            [Pure, SetterThrows]

--- a/dom/webidl/HTMLFrameElement.webidl
+++ b/dom/webidl/HTMLFrameElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#htmlframeelement
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#htmlframeelement
+[HTMLConstructor]
 interface HTMLFrameElement : HTMLElement {
            [SetterThrows]
            attribute DOMString name;
            [SetterThrows]
            attribute DOMString scrolling;
            [SetterThrows]
            attribute DOMString src;
            [SetterThrows]

--- a/dom/webidl/HTMLFrameSetElement.webidl
+++ b/dom/webidl/HTMLFrameSetElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLFrameSetElement : HTMLElement {
   [SetterThrows]
   attribute DOMString cols;
   [SetterThrows]
   attribute DOMString rows;
 };
 
 HTMLFrameSetElement implements WindowEventHandlers;

--- a/dom/webidl/HTMLHRElement.webidl
+++ b/dom/webidl/HTMLHRElement.webidl
@@ -7,16 +7,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-hr-element
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-hr-element
+[HTMLConstructor]
 interface HTMLHRElement : HTMLElement {
 };
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
 partial interface HTMLHRElement {
            [SetterThrows]
            attribute DOMString align;
            [SetterThrows]

--- a/dom/webidl/HTMLHeadElement.webidl
+++ b/dom/webidl/HTMLHeadElement.webidl
@@ -7,10 +7,11 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-head-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-head-element
+[HTMLConstructor]
 interface HTMLHeadElement : HTMLElement {};
 

--- a/dom/webidl/HTMLHeadingElement.webidl
+++ b/dom/webidl/HTMLHeadingElement.webidl
@@ -7,16 +7,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-h1,-h2,-h3,-h4,-h5,-and-h6-elements
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-h1,-h2,-h3,-h4,-h5,-and-h6-elements
+[HTMLConstructor]
 interface HTMLHeadingElement : HTMLElement {
 };
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
 partial interface HTMLHeadingElement {
            [SetterThrows]
            attribute DOMString align;
 };

--- a/dom/webidl/HTMLHtmlElement.webidl
+++ b/dom/webidl/HTMLHtmlElement.webidl
@@ -8,15 +8,16 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-html-element
+[HTMLConstructor]
 interface HTMLHtmlElement : HTMLElement {};
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
 partial interface HTMLHtmlElement {
            [SetterThrows, Pure]
            attribute DOMString version;
 };

--- a/dom/webidl/HTMLIFrameElement.webidl
+++ b/dom/webidl/HTMLIFrameElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-iframe-element
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLIFrameElement : HTMLElement {
   [SetterThrows, Pure]
            attribute DOMString src;
   [SetterThrows, Pure]
            attribute DOMString srcdoc;
   [SetterThrows, Pure]
            attribute DOMString name;
   [PutForwards=value] readonly attribute DOMTokenList sandbox;

--- a/dom/webidl/HTMLImageElement.webidl
+++ b/dom/webidl/HTMLImageElement.webidl
@@ -11,17 +11,18 @@
  * and create derivative works of this document.
  */
 
 interface imgINotificationObserver;
 interface imgIRequest;
 interface URI;
 interface nsIStreamListener;
 
-[NamedConstructor=Image(optional unsigned long width, optional unsigned long height)]
+[HTMLConstructor,
+ NamedConstructor=Image(optional unsigned long width, optional unsigned long height)]
 interface HTMLImageElement : HTMLElement {
            [SetterThrows]
            attribute DOMString alt;
            [SetterThrows]
            attribute DOMString src;
            [SetterThrows]
            attribute DOMString srcset;
            [SetterThrows]

--- a/dom/webidl/HTMLInputElement.webidl
+++ b/dom/webidl/HTMLInputElement.webidl
@@ -16,16 +16,17 @@ enum SelectionMode {
   "select",
   "start",
   "end",
   "preserve",
 };
 
 interface nsIControllers;
 
+[HTMLConstructor]
 interface HTMLInputElement : HTMLElement {
   [Pure, SetterThrows]
            attribute DOMString accept;
   [Pure, SetterThrows]
            attribute DOMString alt;
   [Pure, SetterThrows]
            attribute DOMString autocomplete;
   [Pure, SetterThrows]

--- a/dom/webidl/HTMLLIElement.webidl
+++ b/dom/webidl/HTMLLIElement.webidl
@@ -8,16 +8,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-li-element
+[HTMLConstructor]
 interface HTMLLIElement : HTMLElement {
            [SetterThrows, Pure]
            attribute long value;
 };
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
 partial interface HTMLLIElement {
            [SetterThrows, Pure]

--- a/dom/webidl/HTMLLabelElement.webidl
+++ b/dom/webidl/HTMLLabelElement.webidl
@@ -6,13 +6,14 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLLabelElement : HTMLElement {
   readonly attribute HTMLFormElement? form;
            attribute DOMString htmlFor;
   readonly attribute HTMLElement? control;
 };

--- a/dom/webidl/HTMLLegendElement.webidl
+++ b/dom/webidl/HTMLLegendElement.webidl
@@ -8,16 +8,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-legend-element
+[HTMLConstructor]
 interface HTMLLegendElement : HTMLElement {
   readonly attribute HTMLFormElement? form;
 };
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
 partial interface HTMLLegendElement {
            [SetterThrows]
            attribute DOMString align;

--- a/dom/webidl/HTMLLinkElement.webidl
+++ b/dom/webidl/HTMLLinkElement.webidl
@@ -7,16 +7,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-link-element
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-link-element
+[HTMLConstructor]
 interface HTMLLinkElement : HTMLElement {
   [Pure]
            attribute boolean disabled;
   [SetterThrows, Pure]
            attribute DOMString href;
   [SetterThrows, Pure]
            attribute DOMString? crossOrigin;
   [SetterThrows, Pure]

--- a/dom/webidl/HTMLMapElement.webidl
+++ b/dom/webidl/HTMLMapElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-map-element
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-map-element
+[HTMLConstructor]
 interface HTMLMapElement : HTMLElement {
   [SetterThrows, Pure]
            attribute DOMString name;
   [Constant]
   readonly attribute HTMLCollection areas;
   // Not supported yet.
   //readonly attribute HTMLCollection images;
 };

--- a/dom/webidl/HTMLMenuElement.webidl
+++ b/dom/webidl/HTMLMenuElement.webidl
@@ -10,16 +10,17 @@
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 interface MenuBuilder;
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-menu-element
+[HTMLConstructor]
 interface HTMLMenuElement : HTMLElement {
            [SetterThrows]
            attribute DOMString type;
            [SetterThrows]
            attribute DOMString label;
 };
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis

--- a/dom/webidl/HTMLMenuItemElement.webidl
+++ b/dom/webidl/HTMLMenuItemElement.webidl
@@ -7,16 +7,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-menuitem-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-menuitem-element
+[HTMLConstructor]
 interface HTMLMenuItemElement : HTMLElement {
            [SetterThrows]
            attribute DOMString type;
            [SetterThrows]
            attribute DOMString label;
            [SetterThrows]
            attribute DOMString icon;
            [SetterThrows]

--- a/dom/webidl/HTMLMetaElement.webidl
+++ b/dom/webidl/HTMLMetaElement.webidl
@@ -7,16 +7,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-meta-element
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-meta-element
+[HTMLConstructor]
 interface HTMLMetaElement : HTMLElement {
   [SetterThrows, Pure]
            attribute DOMString name;
   [SetterThrows, Pure]
            attribute DOMString httpEquiv;
   [SetterThrows, Pure]
            attribute DOMString content;
 };

--- a/dom/webidl/HTMLMeterElement.webidl
+++ b/dom/webidl/HTMLMeterElement.webidl
@@ -7,16 +7,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-meter-element	
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-meter-element
+[HTMLConstructor]
 interface HTMLMeterElement : HTMLElement {
            [SetterThrows]
            attribute double value;
            [SetterThrows]
            attribute double min;
            [SetterThrows]
            attribute double max;
            [SetterThrows]

--- a/dom/webidl/HTMLModElement.webidl
+++ b/dom/webidl/HTMLModElement.webidl
@@ -6,14 +6,15 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#attributes-common-to-ins-and-del-elements
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#attributes-common-to-ins-and-del-elements
+[HTMLConstructor]
 interface HTMLModElement : HTMLElement {
   [SetterThrows, Pure]
            attribute DOMString cite;
   [SetterThrows, Pure]
            attribute DOMString dateTime;
 };

--- a/dom/webidl/HTMLOListElement.webidl
+++ b/dom/webidl/HTMLOListElement.webidl
@@ -8,16 +8,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-ol-element
+[HTMLConstructor]
 interface HTMLOListElement : HTMLElement {
            [SetterThrows]
            attribute boolean reversed;
            [SetterThrows]
            attribute long start;
            [SetterThrows]
            attribute DOMString type;
 };

--- a/dom/webidl/HTMLObjectElement.webidl
+++ b/dom/webidl/HTMLObjectElement.webidl
@@ -8,17 +8,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#HTMLObjectElement-partial
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-object-element
-[NeedResolve, UnsafeInPrerendering]
+[HTMLConstructor, NeedResolve, UnsafeInPrerendering]
 interface HTMLObjectElement : HTMLElement {
   [Pure, SetterThrows]
            attribute DOMString data;
   [Pure, SetterThrows]
            attribute DOMString type;
   [Pure, SetterThrows]
            attribute boolean typeMustMatch;
   [Pure, SetterThrows]

--- a/dom/webidl/HTMLOptGroupElement.webidl
+++ b/dom/webidl/HTMLOptGroupElement.webidl
@@ -6,14 +6,15 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-optgroup-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLOptGroupElement : HTMLElement {
            [SetterThrows]
            attribute boolean disabled;
            [SetterThrows]
            attribute DOMString label;
 };

--- a/dom/webidl/HTMLOptionElement.webidl
+++ b/dom/webidl/HTMLOptionElement.webidl
@@ -6,17 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-option-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
-[NamedConstructor=Option(optional DOMString text, optional DOMString value, optional boolean defaultSelected, optional boolean selected)]
+[HTMLConstructor, NamedConstructor=Option(optional DOMString text, optional DOMString value, optional boolean defaultSelected, optional boolean selected)]
 interface HTMLOptionElement : HTMLElement {
            [SetterThrows]
            attribute boolean disabled;
   readonly attribute HTMLFormElement? form;
            [SetterThrows]
            attribute DOMString label;
            [SetterThrows]
            attribute boolean defaultSelected;

--- a/dom/webidl/HTMLOutputElement.webidl
+++ b/dom/webidl/HTMLOutputElement.webidl
@@ -7,16 +7,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-output-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-output-element
+[HTMLConstructor]
 interface HTMLOutputElement : HTMLElement {
   [PutForwards=value, Constant]
   readonly attribute DOMTokenList htmlFor;
   readonly attribute HTMLFormElement? form;
   [SetterThrows, Pure]
            attribute DOMString name;
 
   [Constant]

--- a/dom/webidl/HTMLParagraphElement.webidl
+++ b/dom/webidl/HTMLParagraphElement.webidl
@@ -7,16 +7,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-p-element
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-p-element
+[HTMLConstructor]
 interface HTMLParagraphElement : HTMLElement {
 };
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
 partial interface HTMLParagraphElement {
            [SetterThrows]
            attribute DOMString align;
 };

--- a/dom/webidl/HTMLParamElement.webidl
+++ b/dom/webidl/HTMLParamElement.webidl
@@ -8,16 +8,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-param-element
+[HTMLConstructor]
 interface HTMLParamElement : HTMLElement {
            [SetterThrows, Pure]
            attribute DOMString name;
            [SetterThrows, Pure]
            attribute DOMString value;
 };
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis

--- a/dom/webidl/HTMLPictureElement.webidl
+++ b/dom/webidl/HTMLPictureElement.webidl
@@ -1,8 +1,9 @@
 /* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+[HTMLConstructor]
 interface HTMLPictureElement : HTMLElement {
 };

--- a/dom/webidl/HTMLPreElement.webidl
+++ b/dom/webidl/HTMLPreElement.webidl
@@ -7,16 +7,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-pre-element
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-pre-element
+[HTMLConstructor]
 interface HTMLPreElement : HTMLElement {
 };
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
 partial interface HTMLPreElement {
            [SetterThrows]
            attribute long width;
 };

--- a/dom/webidl/HTMLProgressElement.webidl
+++ b/dom/webidl/HTMLProgressElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-progress-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLProgressElement : HTMLElement {
            [SetterThrows]
            attribute double value;
            [SetterThrows]
            attribute double max;
   readonly attribute double position;
 
   /**

--- a/dom/webidl/HTMLQuoteElement.webidl
+++ b/dom/webidl/HTMLQuoteElement.webidl
@@ -7,13 +7,14 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-blockquote-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-blockquote-element
+[HTMLConstructor]
 interface HTMLQuoteElement : HTMLElement {
            [SetterThrows, Pure]
            attribute DOMString cite;
 };
 

--- a/dom/webidl/HTMLScriptElement.webidl
+++ b/dom/webidl/HTMLScriptElement.webidl
@@ -3,16 +3,17 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  *
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-script-element
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  */
 
+[HTMLConstructor]
 interface HTMLScriptElement : HTMLElement {
   [SetterThrows]
   attribute DOMString src;
   [SetterThrows]
   attribute DOMString type;
   [SetterThrows]
   attribute DOMString charset;
   [SetterThrows]

--- a/dom/webidl/HTMLSelectElement.webidl
+++ b/dom/webidl/HTMLSelectElement.webidl
@@ -2,16 +2,17 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  *
  * The origin of this IDL file is
  * http://www.whatwg.org/html/#the-select-element
  */
 
+[HTMLConstructor]
 interface HTMLSelectElement : HTMLElement {
   [SetterThrows, Pure]
            attribute boolean autofocus;
   [Pref="dom.forms.autocomplete.experimental", SetterThrows, Pure]
            attribute DOMString autocomplete;
   [SetterThrows, Pure]
            attribute boolean disabled;
   [Pure]

--- a/dom/webidl/HTMLSourceElement.webidl
+++ b/dom/webidl/HTMLSourceElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-source-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLSourceElement : HTMLElement {
            [SetterThrows]
            attribute DOMString src;
            [SetterThrows]
            attribute DOMString type;
 };
 
 partial interface HTMLSourceElement {

--- a/dom/webidl/HTMLSpanElement.webidl
+++ b/dom/webidl/HTMLSpanElement.webidl
@@ -7,9 +7,10 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-span-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-span-element
+[HTMLConstructor]
 interface HTMLSpanElement : HTMLElement {};

--- a/dom/webidl/HTMLStyleElement.webidl
+++ b/dom/webidl/HTMLStyleElement.webidl
@@ -3,16 +3,17 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  *
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-style-element
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  */
 
+[HTMLConstructor]
 interface HTMLStyleElement : HTMLElement {
            [Pure]
            attribute boolean disabled;
            [SetterThrows, Pure]
            attribute DOMString media;
            [SetterThrows, Pure]
            attribute DOMString type;
            [SetterThrows, Pure]

--- a/dom/webidl/HTMLTableCaptionElement.webidl
+++ b/dom/webidl/HTMLTableCaptionElement.webidl
@@ -6,14 +6,15 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLTableCaptionElement : HTMLElement {};
 
 partial interface HTMLTableCaptionElement {
            [SetterThrows]
            attribute DOMString align;
 };

--- a/dom/webidl/HTMLTableCellElement.webidl
+++ b/dom/webidl/HTMLTableCellElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLTableCellElement : HTMLElement {
            [SetterThrows]
            attribute unsigned long colSpan;
            [SetterThrows]
            attribute unsigned long rowSpan;
   //[PutForwards=value] readonly attribute DOMTokenList headers;
            [SetterThrows]
            attribute DOMString headers;

--- a/dom/webidl/HTMLTableColElement.webidl
+++ b/dom/webidl/HTMLTableColElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLTableColElement : HTMLElement {
            [SetterThrows]
            attribute unsigned long span;
 };
 
 partial interface HTMLTableColElement {
            [SetterThrows]
            attribute DOMString align;

--- a/dom/webidl/HTMLTableElement.webidl
+++ b/dom/webidl/HTMLTableElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLTableElement : HTMLElement {
            [SetterThrows]
            attribute HTMLTableCaptionElement? caption;
   HTMLElement createCaption();
   void deleteCaption();
            [SetterThrows]
            attribute HTMLTableSectionElement? tHead;
   HTMLElement createTHead();

--- a/dom/webidl/HTMLTableRowElement.webidl
+++ b/dom/webidl/HTMLTableRowElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLTableRowElement : HTMLElement {
   readonly attribute long rowIndex;
   readonly attribute long sectionRowIndex;
   readonly attribute HTMLCollection cells;
   [Throws]
   HTMLElement insertCell(optional long index = -1);
   [Throws]
   void deleteCell(long index);

--- a/dom/webidl/HTMLTableSectionElement.webidl
+++ b/dom/webidl/HTMLTableSectionElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLTableSectionElement : HTMLElement {
   readonly attribute HTMLCollection rows;
   [Throws]
   HTMLElement insertRow(optional long index = -1);
   [Throws]
   void deleteRow(long index);
 };
 

--- a/dom/webidl/HTMLTemplateElement.webidl
+++ b/dom/webidl/HTMLTemplateElement.webidl
@@ -4,12 +4,13 @@
  *
  * The origin of this IDL file is
  * https://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/templates/index.html
  *
  * Copyright © 2012 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C
  * liability, trademark and document use rules apply.
  */
 
+[HTMLConstructor]
 interface HTMLTemplateElement : HTMLElement {
     readonly attribute DocumentFragment content;
 };
 

--- a/dom/webidl/HTMLTextAreaElement.webidl
+++ b/dom/webidl/HTMLTextAreaElement.webidl
@@ -9,16 +9,17 @@
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 interface nsIEditor;
 interface MozControllers;
 
+[HTMLConstructor]
 interface HTMLTextAreaElement : HTMLElement {
            // attribute DOMString autocomplete;
   [SetterThrows, Pure]
            attribute boolean autofocus;
   [SetterThrows, Pure]
            attribute unsigned long cols;
            // attribute DOMString dirName;
   [SetterThrows, Pure]

--- a/dom/webidl/HTMLTimeElement.webidl
+++ b/dom/webidl/HTMLTimeElement.webidl
@@ -2,12 +2,13 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  *
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/multipage/text-level-semantics.html#the-time-element
  */
 
+[HTMLConstructor]
 interface HTMLTimeElement : HTMLElement {
            [SetterThrows]
            attribute DOMString dateTime;
 };

--- a/dom/webidl/HTMLTitleElement.webidl
+++ b/dom/webidl/HTMLTitleElement.webidl
@@ -2,12 +2,13 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  *
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-title-element
  */
 
+[HTMLConstructor]
 interface HTMLTitleElement : HTMLElement {
            [Throws]
            attribute DOMString text;
 };

--- a/dom/webidl/HTMLTrackElement.webidl
+++ b/dom/webidl/HTMLTrackElement.webidl
@@ -2,16 +2,17 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  *
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-track-element
  */
 
+[HTMLConstructor]
 interface HTMLTrackElement : HTMLElement {
   [SetterThrows, Pure]
   attribute DOMString kind;
   [SetterThrows, Pure]
   attribute DOMString src;
   [SetterThrows, Pure]
   attribute DOMString srclang;
   [SetterThrows, Pure]

--- a/dom/webidl/HTMLUListElement.webidl
+++ b/dom/webidl/HTMLUListElement.webidl
@@ -8,16 +8,17 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-ul-element
+[HTMLConstructor]
 interface HTMLUListElement : HTMLElement {
 };
 
 // http://www.whatwg.org/specs/web-apps/current-work/#other-elements,-attributes-and-apis
 partial interface HTMLUListElement {
            [SetterThrows]
            attribute boolean compact;
            [SetterThrows]

--- a/dom/webidl/HTMLVideoElement.webidl
+++ b/dom/webidl/HTMLVideoElement.webidl
@@ -6,16 +6,17 @@
  * The origin of this IDL file is
  * http://www.whatwg.org/specs/web-apps/current-work/#the-video-element
  *
  * © Copyright 2004-2011 Apple Computer, Inc., Mozilla Foundation, and
  * Opera Software ASA. You are granted a license to use, reproduce
  * and create derivative works of this document.
  */
 
+[HTMLConstructor]
 interface HTMLVideoElement : HTMLMediaElement {
   [SetterThrows]
            attribute unsigned long width;
   [SetterThrows]
            attribute unsigned long height;
   readonly attribute unsigned long videoWidth;
   readonly attribute unsigned long videoHeight;
   [SetterThrows]