--- a/dom/browser-element/BrowserElementChildPreload.js
+++ b/dom/browser-element/BrowserElementChildPreload.js
@@ -663,17 +663,17 @@ BrowserElementChild.prototype = {
     sendAsyncMsg('scrollviewchange', detail);
   },
 
   _ClickHandler: function(e) {
 
     let isHTMLLink = node =>
         ((ChromeUtils.getClassName(node) === "HTMLAnchorElement" && node.href) ||
          (ChromeUtils.getClassName(node) === "HTMLAreaElement" && node.href) ||
-         node instanceof Ci.nsIDOMHTMLLinkElement);
+         ChromeUtils.getClassName(node) === "HTMLLinkElement");
 
     // Open in a new tab if middle click or ctrl/cmd-click,
     // and e.target is a link or inside a link.
     if ((Services.appinfo.OS == 'Darwin' && e.metaKey) ||
         (Services.appinfo.OS != 'Darwin' && e.ctrlKey) ||
          e.button == 1) {
 
       let node = e.target;

--- a/dom/html/HTMLLinkElement.cpp
+++ b/dom/html/HTMLLinkElement.cpp
@@ -72,61 +72,36 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(HTMLLinkElement,
                                                 nsGenericHTMLElement)
   tmp->nsStyleLinkElement::Unlink();
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mRelList)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED(HTMLLinkElement,
                                              nsGenericHTMLElement,
-                                             nsIDOMHTMLLinkElement,
                                              nsIStyleSheetLinkingElement,
                                              Link)
 
 NS_IMPL_ELEMENT_CLONE(HTMLLinkElement)
 
 bool
 HTMLLinkElement::Disabled()
 {
   StyleSheet* ss = GetSheet();
   return ss && ss->Disabled();
 }
 
-NS_IMETHODIMP
-HTMLLinkElement::GetMozDisabled(bool* aDisabled)
-{
-  *aDisabled = Disabled();
-  return NS_OK;
-}
-
 void
 HTMLLinkElement::SetDisabled(bool aDisabled)
 {
   if (StyleSheet* ss = GetSheet()) {
     ss->SetDisabled(aDisabled);
   }
 }
 
-NS_IMETHODIMP
-HTMLLinkElement::SetMozDisabled(bool aDisabled)
-{
-  SetDisabled(aDisabled);
-  return NS_OK;
-}
-
-
-NS_IMPL_STRING_ATTR(HTMLLinkElement, Charset, charset)
-NS_IMPL_URI_ATTR(HTMLLinkElement, Href, href)
-NS_IMPL_STRING_ATTR(HTMLLinkElement, Hreflang, hreflang)
-NS_IMPL_STRING_ATTR(HTMLLinkElement, Media, media)
-NS_IMPL_STRING_ATTR(HTMLLinkElement, Rel, rel)
-NS_IMPL_STRING_ATTR(HTMLLinkElement, Rev, rev)
-NS_IMPL_STRING_ATTR(HTMLLinkElement, Target, target)
-NS_IMPL_STRING_ATTR(HTMLLinkElement, Type, type)
-
 void
 HTMLLinkElement::OnDNSPrefetchRequested()
 {
   UnsetFlags(HTML_LINK_DNS_PREFETCH_DEFERRED);
   SetFlags(HTML_LINK_DNS_PREFETCH_REQUESTED);
 }
 
 void

--- a/dom/html/HTMLLinkElement.h
+++ b/dom/html/HTMLLinkElement.h
@@ -5,41 +5,37 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef mozilla_dom_HTMLLinkElement_h
 #define mozilla_dom_HTMLLinkElement_h
 
 #include "mozilla/Attributes.h"
 #include "mozilla/dom/Link.h"
 #include "nsGenericHTMLElement.h"
-#include "nsIDOMHTMLLinkElement.h"
 #include "nsStyleLinkElement.h"
 
 namespace mozilla {
 class EventChainPostVisitor;
 class EventChainPreVisitor;
 namespace dom {
 
 class HTMLLinkElement final : public nsGenericHTMLElement,
-                              public nsIDOMHTMLLinkElement,
                               public nsStyleLinkElement,
                               public Link
 {
 public:
   explicit HTMLLinkElement(already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo);
 
   // nsISupports
   NS_DECL_ISUPPORTS_INHERITED
 
   // CC
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(HTMLLinkElement,
                                            nsGenericHTMLElement)
 
-  // nsIDOMHTMLLinkElement
-  NS_DECL_NSIDOMHTMLLINKELEMENT
   NS_IMPL_FROMCONTENT_HTML_WITH_TAG(HTMLLinkElement, link);
   NS_DECL_ADDSIZEOFEXCLUDINGTHIS
 
   void LinkAdded();
   void LinkRemoved();
 
   // nsIDOMEventTarget
   virtual nsresult GetEventTargetParent(
@@ -80,73 +76,101 @@ public:
 
   virtual void OnDNSPrefetchDeferred() override;
   virtual void OnDNSPrefetchRequested() override;
   virtual bool HasDeferredDNSPrefetchRequest() override;
 
   // WebIDL
   bool Disabled();
   void SetDisabled(bool aDisabled);
-  // XPCOM GetHref is fine.
+
+  void GetHref(nsAString& aValue)
+  {
+    GetURIAttr(nsGkAtoms::href, nullptr, aValue);
+  }
   void SetHref(const nsAString& aHref, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::href, aHref, aRv);
   }
   void GetCrossOrigin(nsAString& aResult)
   {
     // Null for both missing and invalid defaults is ok, since we
     // always parse to an enum value, so we don't need an invalid
     // default, and we _want_ the missing default to be null.
     GetEnumAttr(nsGkAtoms::crossorigin, nullptr, aResult);
   }
   void SetCrossOrigin(const nsAString& aCrossOrigin, ErrorResult& aError)
   {
     SetOrRemoveNullableStringAttr(nsGkAtoms::crossorigin, aCrossOrigin, aError);
   }
-  // XPCOM GetRel is fine.
+  // nsAString for WebBrowserPersistLocalDocument
+  void GetRel(nsAString& aValue)
+  {
+    GetHTMLAttr(nsGkAtoms::rel, aValue);
+  }
   void SetRel(const nsAString& aRel, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::rel, aRel, aRv);
   }
   nsDOMTokenList* RelList();
-  // XPCOM GetMedia is fine.
+  void GetMedia(DOMString& aValue)
+  {
+    GetHTMLAttr(nsGkAtoms::media, aValue);
+  }
   void SetMedia(const nsAString& aMedia, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::media, aMedia, aRv);
   }
-  // XPCOM GetHreflang is fine.
+  void GetHreflang(DOMString& aValue)
+  {
+    GetHTMLAttr(nsGkAtoms::hreflang, aValue);
+  }
   void SetHreflang(const nsAString& aHreflang, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::hreflang, aHreflang, aRv);
   }
   void GetAs(nsAString& aResult);
   void SetAs(const nsAString& aAs, ErrorResult& aRv)
   {
     SetAttr(nsGkAtoms::as ,aAs, aRv);
   }
   nsDOMTokenList* Sizes()
   {
     return GetTokenList(nsGkAtoms::sizes);
   }
-  // XPCOM GetType is fine.
+  void GetType(DOMString& aValue)
+  {
+    GetHTMLAttr(nsGkAtoms::type, aValue);
+  }
   void SetType(const nsAString& aType, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::type, aType, aRv);
   }
-  // XPCOM GetCharset is fine.
+  // Requires nsresult return for nsStyleLinkElement override.
+  nsresult GetCharset(nsAString& aValue) override
+  {
+    GetHTMLAttr(nsGkAtoms::charset, aValue);
+    return NS_OK;
+  }
   void SetCharset(const nsAString& aCharset, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::charset, aCharset, aRv);
   }
-  // XPCOM GetRev is fine.
+  void GetRev(DOMString& aValue)
+  {
+    GetHTMLAttr(nsGkAtoms::rev, aValue);
+  }
   void SetRev(const nsAString& aRev, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::rev, aRev, aRv);
   }
-  // XPCOM GetTarget is fine.
+  void GetTarget(DOMString& aValue)
+  {
+    GetHTMLAttr(nsGkAtoms::target, aValue);
+  }
   void SetTarget(const nsAString& aTarget, ErrorResult& aRv)
   {
     SetHTMLAttr(nsGkAtoms::target, aTarget, aRv);
   }
   void GetIntegrity(nsAString& aIntegrity) const
   {
     GetHTMLAttr(nsGkAtoms::integrity, aIntegrity);
   }

--- a/dom/interfaces/html/moz.build
+++ b/dom/interfaces/html/moz.build
@@ -13,17 +13,16 @@ XPIDL_SOURCES += [
     'nsIDOMHTMLCollection.idl',
     'nsIDOMHTMLDocument.idl',
     'nsIDOMHTMLElement.idl',
     'nsIDOMHTMLFormElement.idl',
     'nsIDOMHTMLHtmlElement.idl',
     'nsIDOMHTMLIFrameElement.idl',
     'nsIDOMHTMLImageElement.idl',
     'nsIDOMHTMLInputElement.idl',
-    'nsIDOMHTMLLinkElement.idl',
     'nsIDOMHTMLMediaElement.idl',
     'nsIDOMHTMLMenuItemElement.idl',
     'nsIDOMHTMLOptionElement.idl',
     'nsIDOMHTMLOptionsCollection.idl',
     'nsIDOMHTMLScriptElement.idl',
     'nsIDOMHTMLSelectElement.idl',
     'nsIDOMHTMLSourceElement.idl',
     'nsIDOMHTMLTextAreaElement.idl',

deleted file mode 100644
--- a/dom/interfaces/html/nsIDOMHTMLLinkElement.idl
+++ /dev/null
@@ -1,32 +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 nsIDOMHTMLLinkElement interface is the interface to a [X]HTML
- * link 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/
- */
-
-[uuid(ee50b7ab-0015-4fbe-89e0-e3feacd4ffde)]
-interface nsIDOMHTMLLinkElement : nsISupports
-{
-           [binaryname(MozDisabled)]
-           attribute boolean          disabled;
-           attribute DOMString        charset;
-           attribute DOMString        href;
-           attribute DOMString        hreflang;
-           attribute DOMString        media;
-           attribute DOMString        rel;
-           attribute DOMString        rev;
-           attribute DOMString        target;
-           attribute DOMString        type;
-};

--- a/dom/webbrowserpersist/WebBrowserPersistLocalDocument.cpp
+++ b/dom/webbrowserpersist/WebBrowserPersistLocalDocument.cpp
@@ -4,16 +4,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "WebBrowserPersistLocalDocument.h"
 #include "WebBrowserPersistDocumentParent.h"
 
 #include "mozilla/dom/HTMLAnchorElement.h"
 #include "mozilla/dom/HTMLAreaElement.h"
 #include "mozilla/dom/HTMLInputElement.h"
+#include "mozilla/dom/HTMLLinkElement.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"
@@ -23,17 +24,16 @@
 #include "nsIDOMComment.h"
 #include "nsIDOMDocument.h"
 #include "nsIDOMHTMLBaseElement.h"
 #include "nsIDOMHTMLCollection.h"
 #include "nsIDOMHTMLDocument.h"
 #include "nsIDOMHTMLIFrameElement.h"
 #include "nsIDOMHTMLImageElement.h"
 #include "nsIDOMHTMLInputElement.h"
-#include "nsIDOMHTMLLinkElement.h"
 #include "nsIDOMHTMLMediaElement.h"
 #include "nsIDOMHTMLOptionElement.h"
 #include "nsIDOMHTMLScriptElement.h"
 #include "nsIDOMHTMLSourceElement.h"
 #include "nsIDOMHTMLTextAreaElement.h"
 #include "nsIDOMMozNamedAttrMap.h"
 #include "nsIDOMNode.h"
 #include "nsIDOMNodeFilter.h"
@@ -530,21 +530,21 @@ ResourceReader::OnWalkDOMNode(nsIDOMNode
     if (content->IsHTMLElement(nsGkAtoms::embed)) {
         return OnWalkAttribute(aNode, "src");
     }
 
     if (content->IsHTMLElement(nsGkAtoms::object)) {
         return OnWalkAttribute(aNode, "data");
     }
 
-    nsCOMPtr<nsIDOMHTMLLinkElement> nodeAsLink = do_QueryInterface(aNode);
-    if (nodeAsLink) {
+    if (auto nodeAsLink = dom::HTMLLinkElement::FromContent(content)) {
         // Test if the link has a rel value indicating it to be a stylesheet
         nsAutoString linkRel;
-        if (NS_SUCCEEDED(nodeAsLink->GetRel(linkRel)) && !linkRel.IsEmpty()) {
+        nodeAsLink->GetRel(linkRel);
+        if (!linkRel.IsEmpty()) {
             nsReadingIterator<char16_t> start;
             nsReadingIterator<char16_t> end;
             nsReadingIterator<char16_t> current;
 
             linkRel.BeginReading(start);
             linkRel.EndReading(end);
 
             // Walk through space delimited string looking for "stylesheet"
@@ -1066,18 +1066,17 @@ PersistNodeFixup::FixupNode(nsIDOMNode *
     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);
-    if (nodeAsLink) {
+    if (content->IsHTMLElement(nsGkAtoms::link)) {
         rv = GetNodeToFixup(aNodeIn, aNodeOut);
         if (NS_SUCCEEDED(rv) && *aNodeOut) {
             // First see if the link represents linked content
             rv = FixupAttribute(*aNodeOut, "href");
             if (NS_FAILED(rv)) {
                 // Perhaps this link is actually an anchor to related content
                 FixupAnchor(*aNodeOut);
             }

--- a/editor/libeditor/HTMLEditorDataTransfer.cpp
+++ b/editor/libeditor/HTMLEditorDataTransfer.cpp
@@ -37,17 +37,16 @@
 #include "nsIContentFilter.h"
 #include "nsIDOMComment.h"
 #include "nsIDOMDocument.h"
 #include "nsIDOMDocumentFragment.h"
 #include "nsIDOMElement.h"
 #include "nsIDOMHTMLIFrameElement.h"
 #include "nsIDOMHTMLImageElement.h"
 #include "nsIDOMHTMLInputElement.h"
-#include "nsIDOMHTMLLinkElement.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
@@ -98,17 +98,16 @@ static const char kPrintingPromptService
 #include "nsIInterfaceRequestor.h"
 #include "nsIInterfaceRequestorUtils.h"
 #include "nsIDocShellTreeOwner.h"
 #include "nsIWebBrowserChrome.h"
 #include "nsIBaseWindow.h"
 #include "nsILayoutHistoryState.h"
 #include "nsFrameManager.h"
 #include "mozilla/ReflowInput.h"
-#include "nsIDOMHTMLLinkElement.h"
 #include "nsIDOMHTMLImageElement.h"
 #include "nsIContentViewerContainer.h"
 #include "nsIContentViewer.h"
 #include "nsIDocumentViewerPrint.h"
 
 #include "nsFocusManager.h"
 #include "nsRange.h"
 #include "nsCDefaultURIFixup.h"

--- a/mobile/android/chrome/content/browser.js
+++ b/mobile/android/chrome/content/browser.js
@@ -3048,17 +3048,17 @@ var NativeWindow = {
     makeURI: function makeURI(aURL, aOriginCharset, aBaseURI) {
       return Services.io.newURI(aURL, aOriginCharset, aBaseURI);
     },
 
     _getLink: function(aElement) {
       if (aElement.nodeType == Ci.nsIDOMNode.ELEMENT_NODE &&
           ((ChromeUtils.getClassName(aElement) === "HTMLAnchorElement" && aElement.href) ||
            (ChromeUtils.getClassName(aElement) === "HTMLAreaElement" && aElement.href) ||
-           aElement instanceof Ci.nsIDOMHTMLLinkElement ||
+           ChromeUtils.getClassName(aElement) === "HTMLLinkElement" ||
            aElement.getAttributeNS(kXLinkNamespace, "type") == "simple")) {
         try {
           let url = this._getLinkURL(aElement);
           return Services.io.newURI(url);
         } catch (e) {}
       }
       return null;
     },

--- a/xpcom/reflect/xptinfo/ShimInterfaceInfo.cpp
+++ b/xpcom/reflect/xptinfo/ShimInterfaceInfo.cpp
@@ -50,17 +50,16 @@
 #include "nsIDOMHTMLCollection.h"
 #include "nsIDOMHTMLDocument.h"
 #include "nsIDOMHTMLElement.h"
 #include "nsIDOMHTMLFormElement.h"
 #include "nsIDOMHTMLHtmlElement.h"
 #include "nsIDOMHTMLIFrameElement.h"
 #include "nsIDOMHTMLImageElement.h"
 #include "nsIDOMHTMLInputElement.h"
-#include "nsIDOMHTMLLinkElement.h"
 #include "nsIDOMHTMLMediaElement.h"
 #include "nsIDOMHTMLMenuItemElement.h"
 #include "nsIDOMHTMLOptionElement.h"
 #include "nsIDOMHTMLOptionsCollection.h"
 #include "nsIDOMHTMLScriptElement.h"
 #include "nsIDOMHTMLSelectElement.h"
 #include "nsIDOMHTMLSourceElement.h"
 #include "nsIDOMHTMLTextAreaElement.h"
@@ -159,17 +158,16 @@
 #include "mozilla/dom/HTMLDocumentBinding.h"
 #include "mozilla/dom/HTMLElementBinding.h"
 #include "mozilla/dom/HTMLFormElementBinding.h"
 #include "mozilla/dom/HTMLFrameSetElementBinding.h"
 #include "mozilla/dom/HTMLHtmlElementBinding.h"
 #include "mozilla/dom/HTMLIFrameElementBinding.h"
 #include "mozilla/dom/HTMLImageElementBinding.h"
 #include "mozilla/dom/HTMLInputElementBinding.h"
-#include "mozilla/dom/HTMLLinkElementBinding.h"
 #include "mozilla/dom/HTMLMediaElementBinding.h"
 #include "mozilla/dom/HTMLMenuItemElementBinding.h"
 #include "mozilla/dom/HTMLObjectElementBinding.h"
 #include "mozilla/dom/HTMLOptionElementBinding.h"
 #include "mozilla/dom/HTMLOptionsCollectionBinding.h"
 #include "mozilla/dom/HTMLScriptElementBinding.h"
 #include "mozilla/dom/HTMLSelectElementBinding.h"
 #include "mozilla/dom/HTMLSourceElementBinding.h"
@@ -321,17 +319,16 @@ const ComponentsInterfaceShimEntry kComp
   DEFINE_SHIM(HTMLCollection),
   DEFINE_SHIM(HTMLDocument),
   DEFINE_SHIM(HTMLElement),
   DEFINE_SHIM(HTMLFormElement),
   DEFINE_SHIM(HTMLHtmlElement),
   DEFINE_SHIM(HTMLIFrameElement),
   DEFINE_SHIM(HTMLImageElement),
   DEFINE_SHIM(HTMLInputElement),
-  DEFINE_SHIM(HTMLLinkElement),
   DEFINE_SHIM(HTMLMediaElement),
   DEFINE_SHIM(HTMLMenuItemElement),
   DEFINE_SHIM(HTMLOptionElement),
   DEFINE_SHIM(HTMLOptionsCollection),
   DEFINE_SHIM(HTMLScriptElement),
   DEFINE_SHIM(HTMLSelectElement),
   DEFINE_SHIM(HTMLSourceElement),
   DEFINE_SHIM(HTMLTextAreaElement),