--- a/dom/base/nsINode.h
+++ b/dom/base/nsINode.h
@@ -756,19 +756,18 @@ public:
    * @param aPropertyName  name of property to get.
    * @param aStatus        out parameter for storing resulting status.
    *                       Set to NS_PROPTABLE_PROP_NOT_THERE if the property
    *                       is not set.
    * @return               the property. Null if the property is not set
    *                       (though a null return value does not imply the
    *                       property was not set, i.e. it can be set to null).
    */
-  virtual void* GetProperty(uint16_t aCategory,
-                            nsIAtom *aPropertyName,
-                            nsresult *aStatus = nullptr) const;
+  void* GetProperty(uint16_t aCategory, nsIAtom *aPropertyName,
+                    nsresult *aStatus = nullptr) const;
 
   /**
    * Set a property to be associated with this node. This will overwrite an
    * existing value if one exists. The existing value is destroyed using the
    * destructor function given when that value was set.
    *
    * @param aPropertyName  name of property to set.
    * @param aValue         new value of property.
@@ -777,18 +776,17 @@ public:
    * @param aTransfer      if true the property will not be deleted when the
    *                       ownerDocument of the node changes, if false it
    *                       will be deleted.
    *
    * @return NS_PROPTABLE_PROP_OVERWRITTEN (success value) if the property
    *                                       was already set
    * @throws NS_ERROR_OUT_OF_MEMORY if that occurs
    */
-  nsresult SetProperty(nsIAtom *aPropertyName,
-                       void *aValue,
+  nsresult SetProperty(nsIAtom *aPropertyName, void *aValue,
                        NSPropertyDtorFunc aDtor = nullptr,
                        bool aTransfer = false)
   {
     return SetProperty(0, aPropertyName, aValue, aDtor, aTransfer);
   }
 
   /**
    * Set a property to be associated with this node. This will overwrite an
@@ -804,22 +802,21 @@ public:
    *                        ownerDocument of the node changes, if false it
    *                        will be deleted.
    * @param aOldValue [out] previous value of property.
    *
    * @return NS_PROPTABLE_PROP_OVERWRITTEN (success value) if the property
    *                                       was already set
    * @throws NS_ERROR_OUT_OF_MEMORY if that occurs
    */
-  virtual nsresult SetProperty(uint16_t aCategory,
-                               nsIAtom *aPropertyName,
-                               void *aValue,
-                               NSPropertyDtorFunc aDtor = nullptr,
-                               bool aTransfer = false,
-                               void **aOldValue = nullptr);
+  nsresult SetProperty(uint16_t aCategory,
+                       nsIAtom *aPropertyName, void *aValue,
+                       NSPropertyDtorFunc aDtor = nullptr,
+                       bool aTransfer = false,
+                       void **aOldValue = nullptr);
 
   /**
    * A generic destructor for property values allocated with new.
    */
   template<class T>
   static void DeleteProperty(void *, nsIAtom *, void *aPropertyValue, void *)
   {
     delete static_cast<T *>(aPropertyValue);
@@ -838,17 +835,17 @@ public:
 
   /**
    * Destroys a property associated with this node. The value is destroyed
    * using the destruction function given when that value was set.
    *
    * @param aCategory      category of property to destroy.
    * @param aPropertyName  name of property to destroy.
    */
-  virtual void DeleteProperty(uint16_t aCategory, nsIAtom *aPropertyName);
+  void DeleteProperty(uint16_t aCategory, nsIAtom *aPropertyName);
 
   /**
    * Unset a property associated with this node. The value will not be
    * destroyed but rather returned. It is the caller's responsibility to
    * destroy the value after that point.
    *
    * @param aPropertyName  name of property to unset.
    * @param aStatus        out parameter for storing resulting status.
@@ -873,19 +870,18 @@ public:
    * @param aPropertyName  name of property to unset.
    * @param aStatus        out parameter for storing resulting status.
    *                       Set to NS_PROPTABLE_PROP_NOT_THERE if the property
    *                       is not set.
    * @return               the property. Null if the property is not set
    *                       (though a null return value does not imply the
    *                       property was not set, i.e. it can be set to null).
    */
-  virtual void* UnsetProperty(uint16_t aCategory,
-                              nsIAtom *aPropertyName,
-                              nsresult *aStatus = nullptr);
+  void* UnsetProperty(uint16_t aCategory, nsIAtom *aPropertyName,
+                      nsresult *aStatus = nullptr);
 
   bool HasProperties() const
   {
     return HasFlag(NODE_HAS_PROPERTIES);
   }
 
   /**
    * Return the principal of this node.  This is guaranteed to never be a null