--- a/content/html/content/src/HTMLTableColElement.cpp
+++ b/content/html/content/src/HTMLTableColElement.cpp
@@ -29,125 +29,22 @@ HTMLTableColElement::WrapNode(JSContext 
 {
   return HTMLTableColElementBinding::Wrap(aCx, aScope, this);
 }
 
 NS_IMPL_ADDREF_INHERITED(HTMLTableColElement, Element)
 NS_IMPL_RELEASE_INHERITED(HTMLTableColElement, Element)
 
 // QueryInterface implementation for HTMLTableColElement
-NS_INTERFACE_TABLE_HEAD(HTMLTableColElement)
+NS_INTERFACE_MAP_BEGIN(HTMLTableColElement)
   NS_HTML_CONTENT_INTERFACES(nsGenericHTMLElement)
-  NS_INTERFACE_TABLE_INHERITED1(HTMLTableColElement,
-                                nsIDOMHTMLTableColElement)
-  NS_INTERFACE_TABLE_TO_MAP_SEGUE
 NS_ELEMENT_INTERFACE_MAP_END
 
 NS_IMPL_ELEMENT_CLONE(HTMLTableColElement)
 
-NS_IMETHODIMP
-HTMLTableColElement::SetSpan(int32_t aSpan)
-{
-  ErrorResult rv;
-  SetSpan(aSpan, rv);
-  return rv.ErrorCode();
-}
-
-NS_IMETHODIMP
-HTMLTableColElement::GetSpan(int32_t* aSpan)
-{
-  *aSpan = Span();
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-HTMLTableColElement::SetAlign(const nsAString& aAlign)
-{
-  ErrorResult rv;
-  SetAlign(aAlign, rv);
-  return rv.ErrorCode();
-}
-
-NS_IMETHODIMP
-HTMLTableColElement::GetAlign(nsAString& aAlign)
-{
-  nsString align;
-  GetAlign(align);
-  aAlign = align;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-HTMLTableColElement::SetVAlign(const nsAString& aVAlign)
-{
-  ErrorResult rv;
-  SetVAlign(aVAlign, rv);
-  return rv.ErrorCode();
-}
-
-NS_IMETHODIMP
-HTMLTableColElement::GetVAlign(nsAString& aVAlign)
-{
-  nsString vAlign;
-  GetVAlign(vAlign);
-  aVAlign = vAlign;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-HTMLTableColElement::SetCh(const nsAString& aCh)
-{
-  ErrorResult rv;
-  SetCh(aCh, rv);
-  return rv.ErrorCode();
-}
-
-NS_IMETHODIMP
-HTMLTableColElement::GetCh(nsAString& aCh)
-{
-  nsString ch;
-  GetCh(ch);
-  aCh = ch;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-HTMLTableColElement::SetChOff(const nsAString& aChOff)
-{
-  ErrorResult rv;
-  SetChOff(aChOff, rv);
-  return rv.ErrorCode();
-}
-
-NS_IMETHODIMP
-HTMLTableColElement::GetChOff(nsAString& aChOff)
-{
-  nsString chOff;
-  GetChOff(chOff);
-  aChOff = chOff;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-HTMLTableColElement::SetWidth(const nsAString& aWidth)
-{
-  ErrorResult rv;
-  SetWidth(aWidth, rv);
-  return rv.ErrorCode();
-}
-
-NS_IMETHODIMP
-HTMLTableColElement::GetWidth(nsAString& aWidth)
-{
-  nsString width;
-  GetWidth(width);
-  aWidth = width;
-  return NS_OK;
-}
-
 bool
 HTMLTableColElement::ParseAttribute(int32_t aNamespaceID,
                                     nsIAtom* aAttribute,
                                     const nsAString& aValue,
                                     nsAttrValue& aResult)
 {
   if (aNamespaceID == kNameSpaceID_None) {
     /* ignore these attributes, stored simply as strings ch */

--- a/content/html/content/src/HTMLTableColElement.h
+++ b/content/html/content/src/HTMLTableColElement.h
@@ -2,23 +2,22 @@
 /* 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/. */
 #ifndef mozilla_dom_HTMLTableColElement_h
 #define mozilla_dom_HTMLTableColElement_h
 
 #include "mozilla/Attributes.h"
 #include "nsGenericHTMLElement.h"
-#include "nsIDOMHTMLTableColElement.h"
 
 namespace mozilla {
 namespace dom {
 
 class HTMLTableColElement MOZ_FINAL : public nsGenericHTMLElement,
-                                      public nsIDOMHTMLTableColElement
+                                      public nsIDOMHTMLElement
 {
 public:
   HTMLTableColElement(already_AddRefed<nsINodeInfo> aNodeInfo)
     : nsGenericHTMLElement(aNodeInfo)
   {
   }
   virtual ~HTMLTableColElement();
 
@@ -29,19 +28,16 @@ public:
   NS_FORWARD_NSIDOMNODE_TO_NSINODE
 
   // nsIDOMElement
   NS_FORWARD_NSIDOMELEMENT_TO_GENERIC
 
   // nsIDOMHTMLElement
   NS_FORWARD_NSIDOMHTMLELEMENT_TO_GENERIC
 
-  // nsIDOMHTMLTableColElement
-  NS_DECL_NSIDOMHTMLTABLECOLELEMENT
-
   uint32_t Span() const
   {
     return GetIntAttr(nsGkAtoms::span, 1);
   }
   void SetSpan(uint32_t aSpan, ErrorResult& aError)
   {
     SetHTMLIntAttr(nsGkAtoms::span, aSpan, aError);
   }

--- a/dom/interfaces/html/moz.build
+++ b/dom/interfaces/html/moz.build
@@ -58,17 +58,16 @@ XPIDL_SOURCES += [
     'nsIDOMHTMLProgressElement.idl',
     'nsIDOMHTMLQuoteElement.idl',
     'nsIDOMHTMLScriptElement.idl',
     'nsIDOMHTMLSelectElement.idl',
     'nsIDOMHTMLSourceElement.idl',
     'nsIDOMHTMLStyleElement.idl',
     'nsIDOMHTMLTableCaptionElem.idl',
     'nsIDOMHTMLTableCellElement.idl',
-    'nsIDOMHTMLTableColElement.idl',
     'nsIDOMHTMLTableElement.idl',
     'nsIDOMHTMLTextAreaElement.idl',
     'nsIDOMHTMLTitleElement.idl',
     'nsIDOMHTMLUListElement.idl',
     'nsIDOMHTMLUnknownElement.idl',
     'nsIDOMHTMLVideoElement.idl',
     'nsIDOMMediaError.idl',
     'nsIDOMMozBrowserFrame.idl',

deleted file mode 100644
--- a/dom/interfaces/html/nsIDOMHTMLTableColElement.idl
+++ /dev/null
@@ -1,28 +0,0 @@
-/* -*- 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/. */
-
-#include "nsIDOMHTMLElement.idl"
-
-/**
- * The nsIDOMHTMLTableColElement interface is the interface to a
- * [X]HTML col element.
- *
- * This interface is trying to follow the DOM Level 2 HTML specification:
- * http://www.w3.org/TR/DOM-Level-2-HTML/
- *
- * with changes from the work-in-progress WHATWG HTML specification:
- * http://www.whatwg.org/specs/web-apps/current-work/
- */
-
-[scriptable, uuid(cd5a5a33-7101-4d32-987c-337c004fce1a)]
-interface nsIDOMHTMLTableColElement : nsIDOMHTMLElement
-{
-           attribute DOMString        align;
-           attribute DOMString        ch;
-           attribute DOMString        chOff;
-           attribute long             span;
-           attribute DOMString        vAlign;
-           attribute DOMString        width;
-};

--- a/dom/webidl/HTMLTableColElement.webidl
+++ b/dom/webidl/HTMLTableColElement.webidl
@@ -7,18 +7,24 @@
  * 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.
  */
 
 interface HTMLTableColElement : HTMLElement {
+           [SetterThrows]
            attribute unsigned long span;
 };
 
 partial interface HTMLTableColElement {
+           [SetterThrows]
            attribute DOMString align;
+           [SetterThrows]
            attribute DOMString ch;
+           [SetterThrows]
            attribute DOMString chOff;
+           [SetterThrows]
            attribute DOMString vAlign;
+           [SetterThrows]
            attribute DOMString width;
 };