--- a/dom/base/FragmentOrElement.cpp
+++ b/dom/base/FragmentOrElement.cpp
@@ -375,22 +375,16 @@ nsIContent::GetBaseURI(bool aTryUseXHRDo
           // document for the base URI.
           // XXX Will fail with xml:base
           base = binding->PrototypeBinding()->DocURI();
           break;
         }
       }
     }
 
-    nsIURI* explicitBaseURI = elem->GetExplicitBaseURI();
-    if (explicitBaseURI) {
-      base = explicitBaseURI;
-      break;
-    }
-
     // Otherwise check for xml:base attribute
     elem->GetAttr(kNameSpaceID_XML, nsGkAtoms::base, attr);
     if (!attr.IsEmpty()) {
       baseAttrs.AppendElement(attr);
     }
     elem = elem->GetParent();
   } while(elem);
 

--- a/dom/base/nsGkAtomList.h
+++ b/dom/base/nsGkAtomList.h
@@ -2143,17 +2143,16 @@ GK_ATOM(animationEffectsForBeforePropert
 GK_ATOM(animationEffectsForAfterProperty, "AnimationsEffectsForAfterProperty") // EffectSet*
 GK_ATOM(cssPseudoElementBeforeProperty, "CSSPseudoElementBeforeProperty") // CSSPseudoElement*
 GK_ATOM(cssPseudoElementAfterProperty, "CSSPseudoElementAfterProperty") // CSSPseudoElement*
 GK_ATOM(transitionsProperty, "TransitionsProperty")        // FrameTransitions*
 GK_ATOM(transitionsOfBeforeProperty, "TransitionsOfBeforeProperty") // FrameTransitions*
 GK_ATOM(transitionsOfAfterProperty, "TransitionsOfAfterProperty") // FrameTransitions*
 GK_ATOM(genConInitializerProperty, "QuoteNodeProperty")
 GK_ATOM(labelMouseDownPtProperty, "LabelMouseDownPtProperty")
-GK_ATOM(baseURIProperty, "baseURIProperty")
 GK_ATOM(lockedStyleStates, "lockedStyleStates")
 GK_ATOM(apzCallbackTransform, "apzCallbackTransform")
 GK_ATOM(restylableAnonymousNode, "restylableAnonymousNode")
 GK_ATOM(paintRequestTime, "PaintRequestTime")
 GK_ATOM(pseudoProperty, "PseudoProperty")  // CSSPseudoElementType
 
 // Languages for lang-specific transforms
 GK_ATOM(Japanese, "ja")

--- a/dom/base/nsINode.cpp
+++ b/dom/base/nsINode.cpp
@@ -1508,36 +1508,16 @@ nsINode::Unlink(nsINode* tmp)
   }
 
   if (tmp->HasProperties()) {
     nsNodeUtils::UnlinkUserData(tmp);
     tmp->DeleteProperty(nsGkAtoms::keepobjectsalive);
   }
 }
 
-static void
-ReleaseURI(void*, /* aObject*/
-           nsIAtom*, /* aPropertyName */
-           void* aPropertyValue,
-           void* /* aData */)
-{
-  nsIURI* uri = static_cast<nsIURI*>(aPropertyValue);
-  NS_RELEASE(uri);
-}
-
-nsresult
-nsINode::SetExplicitBaseURI(nsIURI* aURI)
-{
-  nsresult rv = SetProperty(nsGkAtoms::baseURIProperty, aURI, ReleaseURI);
-  if (NS_SUCCEEDED(rv)) {
-    NS_ADDREF(aURI);
-  }
-  return rv;
-}
-
 static nsresult
 AdoptNodeIntoOwnerDoc(nsINode *aParent, nsINode *aNode)
 {
   NS_ASSERTION(!aNode->GetParentNode(),
                "Should have removed from parent already");
 
   nsIDocument *doc = aParent->OwnerDoc();
 

--- a/dom/base/nsINode.h
+++ b/dom/base/nsINode.h
@@ -1286,24 +1286,16 @@ public:
    * supports setting a per-node base URI.
    *
    * @return the base URI
    */
   virtual already_AddRefed<nsIURI> GetBaseURI(bool aTryUseXHRDocBaseURI = false) const = 0;
   already_AddRefed<nsIURI> GetBaseURIObject() const;
 
   /**
-   * Facility for explicitly setting a base URI on a node.
-   */
-  nsresult SetExplicitBaseURI(nsIURI* aURI);
-  /**
-   * The explicit base URI, if set, otherwise null
-   */
-
-  /**
    * Return true if the node may be apz aware. There are two cases. One is that
    * the node is apz aware (such as HTMLInputElement with number type). The
    * other is that the node has apz aware listeners. This is a non-virtual
    * function which calls IsNodeApzAwareInternal only when the MayBeApzAware is
    * set. We check the details in IsNodeApzAwareInternal which may be overriden
    * by child classes
    */
   bool IsNodeApzAware() const
@@ -1324,26 +1316,16 @@ public:
   // HTML elements named <shadow> may or may not be HTMLShadowElement.  This is
   // a way to ask an element whether it's an HTMLShadowElement.
   virtual bool IsHTMLShadowElement() const { return false; }
 
   // Elements named <content> may or may not be HTMLContentElement.  This is a
   // way to ask an element whether it's an HTMLContentElement.
   virtual bool IsHTMLContentElement() const { return false; }
 
-protected:
-  nsIURI* GetExplicitBaseURI() const {
-    if (!HasProperties()) {
-      return nullptr;
-    }
-
-    return static_cast<nsIURI*>(GetProperty(nsGkAtoms::baseURIProperty));
-  }
-
-public:
   void GetTextContent(nsAString& aTextContent,
                       mozilla::OOMReporter& aError)
   {
     GetTextContentInternal(aTextContent, aError);
   }
   void SetTextContent(const nsAString& aTextContent,
                       mozilla::ErrorResult& aError)
   {