--- a/docshell/base/nsDocShellTreeOwner.cpp
+++ b/docshell/base/nsDocShellTreeOwner.cpp
@@ -37,17 +37,16 @@
 #include "mozilla/dom/SVGTitleElement.h"
 #include "nsIDOMEvent.h"
 #include "nsIDOMFileList.h"
 #include "nsIDOMMouseEvent.h"
 #include "nsIFormControl.h"
 #include "nsIDOMHTMLInputElement.h"
 #include "nsIDOMHTMLTextAreaElement.h"
 #include "nsIDOMHTMLHtmlElement.h"
-#include "nsIDOMHTMLObjectElement.h"
 #include "nsIDOMHTMLDocument.h"
 #include "nsIImageLoadingContent.h"
 #include "nsIWebNavigation.h"
 #include "nsIDOMHTMLElement.h"
 #include "nsIPresShell.h"
 #include "nsIStringBundle.h"
 #include "nsPIDOMWindow.h"
 #include "nsPIWindowRoot.h"
@@ -1576,23 +1575,21 @@ ChromeContextMenuListener::HandleEvent(n
           targetDOMnode = node;
         }
       }
     }
 
     // always consume events for plugins who may throw their own context menus
     // but not for image objects. Document objects will never be targets or
     // ancestors of targets, so that's OK.
-    nsCOMPtr<nsIDOMHTMLObjectElement> objectElement;
-    if (!(flags & nsIContextMenuListener::CONTEXT_IMAGE)) {
-      objectElement = do_QueryInterface(node);
-    }
-
     nsCOMPtr<nsIContent> content = do_QueryInterface(node);
-    if (objectElement || (content && content->IsHTMLElement(nsGkAtoms::embed))) {
+    if (content &&
+        (content->IsHTMLElement(nsGkAtoms::embed) ||
+         (!(flags & nsIContextMenuListener::CONTEXT_IMAGE) &&
+          content->IsHTMLElement(nsGkAtoms::object)))) {
       return NS_OK;
     }
   }
 
   // Bubble out, looking for items of interest
   do {
     uint16_t nodeType;
     res = node->GetNodeType(&nodeType);

--- a/dom/base/nsObjectLoadingContent.cpp
+++ b/dom/base/nsObjectLoadingContent.cpp
@@ -15,17 +15,16 @@
 #include "nsIConsoleService.h"
 #include "nsIContent.h"
 #include "nsIContentInlines.h"
 #include "nsIDocShell.h"
 #include "nsIDocShellLoadInfo.h"
 #include "nsIDocument.h"
 #include "nsIDOMCustomEvent.h"
 #include "nsIDOMDocument.h"
-#include "nsIDOMHTMLObjectElement.h"
 #include "nsIExternalProtocolHandler.h"
 #include "nsIInterfaceRequestorUtils.h"
 #include "nsIObjectFrame.h"
 #include "nsIOService.h"
 #include "nsIPermissionManager.h"
 #include "nsPluginHost.h"
 #include "nsPluginInstanceOwner.h"
 #include "nsJSNPRuntime.h"
@@ -887,24 +886,24 @@ nsObjectLoadingContent::GetNestedParams(
 
     nsAutoString name;
     element->GetAttribute(NS_LITERAL_STRING("name"), name);
 
     if (name.IsEmpty())
       continue;
 
     nsCOMPtr<nsIContent> parent = element->GetParent();
-    nsCOMPtr<nsIDOMHTMLObjectElement> domObject;
-    while (!domObject && parent) {
-      domObject = do_QueryInterface(parent);
+    RefPtr<HTMLObjectElement> objectElement;
+    while (!objectElement && parent) {
+      objectElement = HTMLObjectElement::FromContent(parent);
       parent = parent->GetParent();
     }
 
-    if (domObject) {
-      parent = do_QueryInterface(domObject);
+    if (objectElement) {
+      parent = objectElement;
     } else {
       continue;
     }
 
     if (parent == ourElement) {
       MozPluginParameter param;
       element->GetAttribute(NS_LITERAL_STRING("name"), param.mName);
       element->GetAttribute(NS_LITERAL_STRING("value"), param.mValue);

--- a/dom/html/HTMLObjectElement.cpp
+++ b/dom/html/HTMLObjectElement.cpp
@@ -93,17 +93,16 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(HTMLObjectElement,
                                                 nsGenericHTMLFormElement)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mValidity)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED(HTMLObjectElement,
                                              nsGenericHTMLFormElement,
-                                             nsIDOMHTMLObjectElement,
                                              imgINotificationObserver,
                                              nsIRequestObserver,
                                              nsIStreamListener,
                                              nsIFrameLoaderOwner,
                                              nsIObjectLoadingContent,
                                              nsIImageLoadingContent,
                                              imgIOnloadBlocker,
                                              nsIChannelEventSink,
@@ -229,22 +228,16 @@ NS_IMETHODIMP
 HTMLObjectElement::PostHandleEvent(EventChainPostVisitor& aVisitor)
 {
   HandleFocusBlurPlugin(this, aVisitor.mEvent);
   return NS_OK;
 }
 
 #endif // #ifdef XP_MACOSX
 
-NS_IMETHODIMP
-HTMLObjectElement::GetForm(nsIDOMHTMLFormElement **aForm)
-{
-  return nsGenericHTMLFormElement::GetForm(aForm);
-}
-
 nsresult
 HTMLObjectElement::BindToTree(nsIDocument *aDocument,
                               nsIContent *aParent,
                               nsIContent *aBindingParent,
                               bool aCompileEventHandlers)
 {
   nsresult rv = nsGenericHTMLFormElement::BindToTree(aDocument, aParent,
                                                      aBindingParent,
@@ -433,50 +426,22 @@ HTMLObjectElement::SubmitNamesValues(HTM
 
   nsAutoString value;
   nsresult rv = pi->GetFormValue(value);
   NS_ENSURE_SUCCESS(rv, rv);
 
   return aFormSubmission->AddNameValuePair(name, value);
 }
 
-NS_IMPL_STRING_ATTR(HTMLObjectElement, Align, align)
-NS_IMPL_STRING_ATTR(HTMLObjectElement, Archive, archive)
-NS_IMPL_STRING_ATTR(HTMLObjectElement, Border, border)
-NS_IMPL_STRING_ATTR(HTMLObjectElement, Code, code)
-NS_IMPL_URI_ATTR(HTMLObjectElement, CodeBase, codebase)
-NS_IMPL_STRING_ATTR(HTMLObjectElement, CodeType, codetype)
-NS_IMPL_URI_ATTR_WITH_BASE(HTMLObjectElement, Data, data, codebase)
-NS_IMPL_BOOL_ATTR(HTMLObjectElement, Declare, declare)
-NS_IMPL_STRING_ATTR(HTMLObjectElement, Height, height)
-NS_IMPL_INT_ATTR(HTMLObjectElement, Hspace, hspace)
-NS_IMPL_STRING_ATTR(HTMLObjectElement, Name, name)
-NS_IMPL_STRING_ATTR(HTMLObjectElement, Standby, standby)
-NS_IMPL_STRING_ATTR(HTMLObjectElement, Type, type)
-NS_IMPL_STRING_ATTR(HTMLObjectElement, UseMap, usemap)
-NS_IMPL_INT_ATTR(HTMLObjectElement, Vspace, vspace)
-NS_IMPL_STRING_ATTR(HTMLObjectElement, Width, width)
-
 int32_t
 HTMLObjectElement::TabIndexDefault()
 {
   return IsFocusableForTabIndex() ? 0 : -1;
 }
 
-NS_IMETHODIMP
-HTMLObjectElement::GetContentDocument(nsIDOMDocument **aContentDocument)
-{
-  NS_ENSURE_ARG_POINTER(aContentDocument);
-
-  nsCOMPtr<nsIDOMDocument> domDoc =
-    do_QueryInterface(GetContentDocument(*nsContentUtils::SubjectPrincipal()));
-  domDoc.forget(aContentDocument);
-  return NS_OK;
-}
-
 nsPIDOMWindowOuter*
 HTMLObjectElement::GetContentWindow(nsIPrincipal& aSubjectPrincipal)
 {
   nsIDocument* doc = GetContentDocument(aSubjectPrincipal);
   if (doc) {
     return doc->GetWindow();
   }
 

--- a/dom/html/HTMLObjectElement.h
+++ b/dom/html/HTMLObjectElement.h
@@ -5,27 +5,25 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef mozilla_dom_HTMLObjectElement_h
 #define mozilla_dom_HTMLObjectElement_h
 
 #include "mozilla/Attributes.h"
 #include "nsGenericHTMLElement.h"
 #include "nsObjectLoadingContent.h"
-#include "nsIDOMHTMLObjectElement.h"
 #include "nsIConstraintValidation.h"
 
 namespace mozilla {
 namespace dom {
 
 class HTMLFormSubmission;
 
 class HTMLObjectElement final : public nsGenericHTMLFormElement
                               , public nsObjectLoadingContent
-                              , public nsIDOMHTMLObjectElement
                               , public nsIConstraintValidation
 {
 public:
   explicit HTMLObjectElement(already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo,
                              FromParser aFromParser = NOT_FROM_PARSER);
 
   // nsISupports
   NS_DECL_ISUPPORTS_INHERITED
@@ -46,19 +44,16 @@ public:
 #endif
 
   // Element
   virtual bool IsInteractiveHTMLContent(bool aIgnoreTabindex) const override;
 
   // EventTarget
   virtual void AsyncEventRunning(AsyncEventDispatcher* aEvent) override;
 
-  // nsIDOMHTMLObjectElement
-  NS_DECL_NSIDOMHTMLOBJECTELEMENT
-
   virtual nsresult BindToTree(nsIDocument *aDocument, nsIContent *aParent,
                               nsIContent *aBindingParent,
                               bool aCompileEventHandlers) override;
   virtual void UnbindFromTree(bool aDeep = true,
                               bool aNullParent = true) override;
 
   virtual bool IsHTMLFocusable(bool aWithMouse, bool *aIsFocusable, int32_t *aTabIndex) override;
   virtual IMEState GetDesiredIMEState() override;
@@ -90,17 +85,20 @@ public:
   nsresult CopyInnerTo(Element* aDest, bool aPreallocateChildren);
 
   void StartObjectLoad() { StartObjectLoad(true, false); }
 
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(HTMLObjectElement,
                                            nsGenericHTMLFormElement)
 
   // Web IDL binding methods
-  // XPCOM GetData is ok; note that it's a URI attribute with a weird base URI
+  void GetData(DOMString& aValue)
+  {
+    GetURIAttr(nsGkAtoms::data, nsGkAtoms::codebase, aValue);
+  }
   void SetData(const nsAString& aValue, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::data, aValue, aRv);
   }
   void GetType(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::type, aValue);
   }
@@ -167,17 +165,20 @@ public:
   void GetArchive(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::archive, aValue);
   }
   void SetArchive(const nsAString& aValue, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::archive, aValue, aRv);
   }
-  // XPCOM GetCode is ok
+  void GetCode(DOMString& aValue)
+  {
+    GetHTMLAttr(nsGkAtoms::code, aValue);
+  }
   void SetCode(const nsAString& aValue, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::code, aValue, aRv);
   }
   bool Declare()
   {
     return GetBoolAttr(nsGkAtoms::declare);
   }
@@ -204,17 +205,20 @@ public:
   uint32_t Vspace()
   {
     return GetUnsignedIntAttr(nsGkAtoms::vspace, 0);
   }
   void SetVspace(uint32_t aValue, ErrorResult& aRv)
   {
     SetUnsignedIntAttr(nsGkAtoms::vspace, aValue, 0, aRv);
   }
-  // XPCOM GetCodebase is ok; note that it's a URI attribute
+  void GetCodeBase(DOMString& aValue)
+  {
+    GetURIAttr(nsGkAtoms::codebase, nullptr, aValue);
+  }
   void SetCodeBase(const nsAString& aValue, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::codebase, aValue, aRv);
   }
   void GetCodeType(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::codetype, aValue);
   }

--- a/dom/interfaces/html/moz.build
+++ b/dom/interfaces/html/moz.build
@@ -20,17 +20,16 @@ XPIDL_SOURCES += [
     'nsIDOMHTMLFrameElement.idl',
     'nsIDOMHTMLHtmlElement.idl',
     'nsIDOMHTMLIFrameElement.idl',
     'nsIDOMHTMLImageElement.idl',
     'nsIDOMHTMLInputElement.idl',
     'nsIDOMHTMLLinkElement.idl',
     'nsIDOMHTMLMediaElement.idl',
     'nsIDOMHTMLMenuItemElement.idl',
-    'nsIDOMHTMLObjectElement.idl',
     'nsIDOMHTMLOptionElement.idl',
     'nsIDOMHTMLOptionsCollection.idl',
     'nsIDOMHTMLScriptElement.idl',
     'nsIDOMHTMLSelectElement.idl',
     'nsIDOMHTMLSourceElement.idl',
     'nsIDOMHTMLTextAreaElement.idl',
     'nsIDOMMozBrowserFrame.idl',
     'nsIDOMTimeRanges.idl',

deleted file mode 100644
--- a/dom/interfaces/html/nsIDOMHTMLObjectElement.idl
+++ /dev/null
@@ -1,43 +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 nsIDOMHTMLObjectElement interface is the interface to a [X]HTML
- * object 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/
- */
-
-interface nsIDOMValidityState;
-
-[uuid(baf443d2-da5d-40c9-be3c-c65a69a25250)]
-interface nsIDOMHTMLObjectElement : nsISupports
-{
-  readonly attribute nsIDOMHTMLFormElement form;
-           attribute DOMString             code;
-           attribute DOMString             align;
-           attribute DOMString             archive;
-           attribute DOMString             border;
-           attribute DOMString             codeBase;
-           attribute DOMString             codeType;
-           attribute DOMString             data;
-           attribute boolean               declare;
-           attribute DOMString             height;
-           attribute long                  hspace;
-           attribute DOMString             name;
-           attribute DOMString             standby;
-           attribute DOMString             type;
-           attribute DOMString             useMap;
-           attribute long                  vspace;
-           attribute DOMString             width;
-  // Introduced in DOM Level 2:
-  readonly attribute nsIDOMDocument        contentDocument;
-};

--- a/dom/plugins/base/nsPluginInstanceOwner.cpp
+++ b/dom/plugins/base/nsPluginInstanceOwner.cpp
@@ -30,17 +30,16 @@ using mozilla::DefaultXDisplay;
 #include "mozilla/Preferences.h"
 #include "nsILinkHandler.h"
 #include "nsIDocShellTreeItem.h"
 #include "nsIWebBrowserChrome.h"
 #include "nsLayoutUtils.h"
 #include "nsIPluginWidget.h"
 #include "nsViewManager.h"
 #include "nsIDocShellTreeOwner.h"
-#include "nsIDOMHTMLObjectElement.h"
 #include "nsIAppShell.h"
 #include "nsIObjectLoadingContent.h"
 #include "nsObjectLoadingContent.h"
 #include "nsAttrName.h"
 #include "nsIFocusManager.h"
 #include "nsFocusManager.h"
 #include "nsIDOMDragEvent.h"
 #include "nsIScriptSecurityManager.h"

--- a/dom/webbrowserpersist/WebBrowserPersistLocalDocument.cpp
+++ b/dom/webbrowserpersist/WebBrowserPersistLocalDocument.cpp
@@ -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/. */
 
 #include "WebBrowserPersistLocalDocument.h"
 #include "WebBrowserPersistDocumentParent.h"
 
 #include "mozilla/dom/HTMLInputElement.h"
+#include "mozilla/dom/HTMLObjectElement.h"
 #include "mozilla/dom/HTMLSharedElement.h"
 #include "mozilla/dom/TabParent.h"
 #include "nsComponentManagerUtils.h"
 #include "nsContentUtils.h"
 #include "nsContentCID.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsFrameLoader.h"
 #include "nsIComponentRegistrar.h"
@@ -25,17 +26,16 @@
 #include "nsIDOMHTMLCollection.h"
 #include "nsIDOMHTMLDocument.h"
 #include "nsIDOMHTMLFrameElement.h"
 #include "nsIDOMHTMLIFrameElement.h"
 #include "nsIDOMHTMLImageElement.h"
 #include "nsIDOMHTMLInputElement.h"
 #include "nsIDOMHTMLLinkElement.h"
 #include "nsIDOMHTMLMediaElement.h"
-#include "nsIDOMHTMLObjectElement.h"
 #include "nsIDOMHTMLOptionElement.h"
 #include "nsIDOMHTMLScriptElement.h"
 #include "nsIDOMHTMLSourceElement.h"
 #include "nsIDOMHTMLTextAreaElement.h"
 #include "nsIDOMMozNamedAttrMap.h"
 #include "nsIDOMNode.h"
 #include "nsIDOMNodeFilter.h"
 #include "nsIDOMNodeList.h"
@@ -527,18 +527,17 @@ ResourceReader::OnWalkDOMNode(nsIDOMNode
     if (content->IsSVGElement(nsGkAtoms::script)) {
         return OnWalkAttribute(aNode, "href", "http://www.w3.org/1999/xlink");
     }
 
     if (content->IsHTMLElement(nsGkAtoms::embed)) {
         return OnWalkAttribute(aNode, "src");
     }
 
-    nsCOMPtr<nsIDOMHTMLObjectElement> nodeAsObject = do_QueryInterface(aNode);
-    if (nodeAsObject) {
+    if (content->IsHTMLElement(nsGkAtoms::object)) {
         return OnWalkAttribute(aNode, "data");
     }
 
     nsCOMPtr<nsIDOMHTMLLinkElement> nodeAsLink = do_QueryInterface(aNode);
     if (nodeAsLink) {
         // Test if the link has a rel value indicating it to be a stylesheet
         nsAutoString linkRel;
         if (NS_SUCCEEDED(nodeAsLink->GetRel(linkRel)) && !linkRel.IsEmpty()) {
@@ -1061,18 +1060,17 @@ PersistNodeFixup::FixupNode(nsIDOMNode *
     if (content->IsHTMLElement(nsGkAtoms::embed)) {
         rv = GetNodeToFixup(aNodeIn, aNodeOut);
         if (NS_SUCCEEDED(rv) && *aNodeOut) {
             FixupAttribute(*aNodeOut, "src");
         }
         return rv;
     }
 
-    nsCOMPtr<nsIDOMHTMLObjectElement> nodeAsObject = do_QueryInterface(aNodeIn);
-    if (nodeAsObject) {
+    if (content->IsHTMLElement(nsGkAtoms::object)) {
         rv = GetNodeToFixup(aNodeIn, aNodeOut);
         if (NS_SUCCEEDED(rv) && *aNodeOut) {
             FixupAttribute(*aNodeOut, "data");
         }
         return rv;
     }
 
     nsCOMPtr<nsIDOMHTMLLinkElement> nodeAsLink = do_QueryInterface(aNodeIn);

--- a/editor/libeditor/HTMLEditorDataTransfer.cpp
+++ b/editor/libeditor/HTMLEditorDataTransfer.cpp
@@ -40,17 +40,16 @@
 #include "nsIDOMDocumentFragment.h"
 #include "nsIDOMElement.h"
 #include "nsIDOMHTMLAnchorElement.h"
 #include "nsIDOMHTMLFrameElement.h"
 #include "nsIDOMHTMLIFrameElement.h"
 #include "nsIDOMHTMLImageElement.h"
 #include "nsIDOMHTMLInputElement.h"
 #include "nsIDOMHTMLLinkElement.h"
-#include "nsIDOMHTMLObjectElement.h"
 #include "nsIDOMHTMLScriptElement.h"
 #include "nsIDOMNode.h"
 #include "nsIDocument.h"
 #include "nsIEditRules.h"
 #include "nsIFile.h"
 #include "nsIInputStream.h"
 #include "nsIMIMEService.h"
 #include "nsNameSpaceManager.h"

--- a/layout/printing/nsPrintEngine.cpp
+++ b/layout/printing/nsPrintEngine.cpp
@@ -37,17 +37,16 @@ static const char sPrintSettingsServiceC
 // Printing Events
 #include "nsPrintPreviewListener.h"
 #include "nsThreadUtils.h"
 
 // Printing
 #include "nsIWebBrowserPrint.h"
 #include "nsIDOMHTMLFrameElement.h"
 #include "nsIDOMHTMLIFrameElement.h"
-#include "nsIDOMHTMLObjectElement.h"
 
 // Print Preview
 #include "imgIContainer.h" // image animation mode constants
 #include "nsIWebBrowserPrint.h" // needed for PrintPreview Navigation constants
 
 // Print Progress
 #include "nsIPrintProgress.h"
 #include "nsIPrintProgressParams.h"

--- a/xpcom/reflect/xptinfo/ShimInterfaceInfo.cpp
+++ b/xpcom/reflect/xptinfo/ShimInterfaceInfo.cpp
@@ -57,17 +57,16 @@
 #include "nsIDOMHTMLFrameElement.h"
 #include "nsIDOMHTMLHtmlElement.h"
 #include "nsIDOMHTMLIFrameElement.h"
 #include "nsIDOMHTMLImageElement.h"
 #include "nsIDOMHTMLInputElement.h"
 #include "nsIDOMHTMLLinkElement.h"
 #include "nsIDOMHTMLMediaElement.h"
 #include "nsIDOMHTMLMenuItemElement.h"
-#include "nsIDOMHTMLObjectElement.h"
 #include "nsIDOMHTMLOptionElement.h"
 #include "nsIDOMHTMLOptionsCollection.h"
 #include "nsIDOMHTMLScriptElement.h"
 #include "nsIDOMHTMLSelectElement.h"
 #include "nsIDOMHTMLSourceElement.h"
 #include "nsIDOMHTMLTextAreaElement.h"
 #include "nsIDOMKeyEvent.h"
 #include "nsIDOMMediaList.h"
@@ -334,17 +333,16 @@ const ComponentsInterfaceShimEntry kComp
   DEFINE_SHIM(HTMLFrameElement),
   DEFINE_SHIM(HTMLHtmlElement),
   DEFINE_SHIM(HTMLIFrameElement),
   DEFINE_SHIM(HTMLImageElement),
   DEFINE_SHIM(HTMLInputElement),
   DEFINE_SHIM(HTMLLinkElement),
   DEFINE_SHIM(HTMLMediaElement),
   DEFINE_SHIM(HTMLMenuItemElement),
-  DEFINE_SHIM(HTMLObjectElement),
   DEFINE_SHIM(HTMLOptionElement),
   DEFINE_SHIM(HTMLOptionsCollection),
   DEFINE_SHIM(HTMLScriptElement),
   DEFINE_SHIM(HTMLSelectElement),
   DEFINE_SHIM(HTMLSourceElement),
   DEFINE_SHIM(HTMLTextAreaElement),
   DEFINE_SHIM(KeyEvent),
   DEFINE_SHIM_WITH_CUSTOM_INTERFACE(nsIListBoxObject, ListBoxObject),