--- a/dom/base/FragmentOrElement.cpp
+++ b/dom/base/FragmentOrElement.cpp
@@ -1209,25 +1209,22 @@ FragmentOrElement::GetBindingParent() co
 
   if (slots) {
     return slots->mBindingParent;
   }
   return nullptr;
 }
 
 nsXBLBinding*
-FragmentOrElement::GetXBLBinding() const
+FragmentOrElement::DoGetXBLBinding() const
 {
-  if (HasFlag(NODE_MAY_BE_IN_BINDING_MNGR)) {
-    nsExtendedDOMSlots* slots = GetExistingExtendedDOMSlots();
-    if (slots) {
-      return slots->mXBLBinding;
-    }
+  MOZ_ASSERT(HasFlag(NODE_MAY_BE_IN_BINDING_MNGR));
+  if (nsExtendedDOMSlots* slots = GetExistingExtendedDOMSlots()) {
+    return slots->mXBLBinding;
   }
-
   return nullptr;
 }
 
 void
 FragmentOrElement::SetXBLBinding(nsXBLBinding* aBinding,
                                  nsBindingManager* aOldBindingManager)
 {
   nsBindingManager* bindingManager;

--- a/dom/base/FragmentOrElement.h
+++ b/dom/base/FragmentOrElement.h
@@ -142,18 +142,18 @@ public:
   virtual nsresult AppendText(const char16_t* aBuffer, uint32_t aLength,
                               bool aNotify) override;
   virtual bool TextIsOnlyWhitespace() override;
   virtual bool ThreadSafeTextIsOnlyWhitespace() const override;
   virtual bool HasTextForTranslation() override;
   virtual void AppendTextTo(nsAString& aResult) override;
   MOZ_MUST_USE
   virtual bool AppendTextTo(nsAString& aResult, const mozilla::fallible_t&) override;
-  virtual nsIContent *GetBindingParent() const override;
-  virtual nsXBLBinding *GetXBLBinding() const override;
+  virtual nsIContent* GetBindingParent() const override;
+  virtual nsXBLBinding* DoGetXBLBinding() const override;
   virtual void SetXBLBinding(nsXBLBinding* aBinding,
                              nsBindingManager* aOldBindingManager = nullptr) override;
   virtual ShadowRoot *GetContainingShadow() const override;
   virtual nsTArray<nsIContent*> &DestInsertionPoints() override;
   virtual nsTArray<nsIContent*> *GetExistingDestInsertionPoints() const override;
   virtual void SetShadowRoot(ShadowRoot* aBinding) override;
   virtual mozilla::dom::HTMLSlotElement* GetAssignedSlot() const override;
   virtual void SetAssignedSlot(mozilla::dom::HTMLSlotElement* aSlot) override;

--- a/dom/base/nsGenericDOMDataNode.cpp
+++ b/dom/base/nsGenericDOMDataNode.cpp
@@ -750,17 +750,17 @@ nsGenericDOMDataNode::GetAssignedSlot() 
 void
 nsGenericDOMDataNode::SetAssignedSlot(HTMLSlotElement* aSlot)
 {
   nsDataSlots *slots = DataSlots();
   slots->mAssignedSlot = aSlot;
 }
 
 nsXBLBinding *
-nsGenericDOMDataNode::GetXBLBinding() const
+nsGenericDOMDataNode::DoGetXBLBinding() const
 {
   return nullptr;
 }
 
 void
 nsGenericDOMDataNode::SetXBLBinding(nsXBLBinding* aBinding,
                                     nsBindingManager* aOldBindingManager)
 {

--- a/dom/base/nsGenericDOMDataNode.h
+++ b/dom/base/nsGenericDOMDataNode.h
@@ -163,18 +163,18 @@ public:
                             const mozilla::fallible_t&) override;
   virtual void SaveSubtreeState() override;
 
 #ifdef DEBUG
   virtual void List(FILE* out, int32_t aIndent) const override;
   virtual void DumpContent(FILE* out, int32_t aIndent, bool aDumpAll) const override;
 #endif
 
-  virtual nsIContent *GetBindingParent() const override;
-  virtual nsXBLBinding *GetXBLBinding() const override;
+  virtual nsIContent* GetBindingParent() const override;
+  virtual nsXBLBinding* DoGetXBLBinding() const override;
   virtual void SetXBLBinding(nsXBLBinding* aBinding,
                              nsBindingManager* aOldBindingManager = nullptr) override;
   virtual mozilla::dom::ShadowRoot *GetContainingShadow() const override;
   virtual nsTArray<nsIContent*> &DestInsertionPoints() override;
   virtual nsTArray<nsIContent*> *GetExistingDestInsertionPoints() const override;
   virtual void SetShadowRoot(mozilla::dom::ShadowRoot* aShadowRoot) override;
   virtual mozilla::dom::HTMLSlotElement* GetAssignedSlot() const override;
   virtual void SetAssignedSlot(mozilla::dom::HTMLSlotElement* aSlot) override;

--- a/dom/base/nsIContent.h
+++ b/dom/base/nsIContent.h
@@ -676,24 +676,33 @@ public:
    * frame) responsible for our construction (and existence).  Used by
    * anonymous content (both XBL-generated and native-anonymous).
    *
    * null for all explicit content (i.e., content reachable from the top
    * of its GetParent() chain via child lists).
    *
    * @return the binding parent
    */
-  virtual nsIContent *GetBindingParent() const = 0;
+  virtual nsIContent* GetBindingParent() const = 0;
 
   /**
    * Gets the current XBL binding that is bound to this element.
    *
    * @return the current binding.
    */
-  virtual nsXBLBinding *GetXBLBinding() const = 0;
+  nsXBLBinding* GetXBLBinding() const
+  {
+    if (!HasFlag(NODE_MAY_BE_IN_BINDING_MNGR)) {
+      return nullptr;
+    }
+
+    return DoGetXBLBinding();
+  }
+
+  virtual nsXBLBinding* DoGetXBLBinding() const = 0;
 
   /**
    * Sets or unsets an XBL binding for this element. Setting a
    * binding on an element that already has a binding will remove the
    * old binding.
    *
    * @param aBinding The binding to bind to this content. If nullptr is
    *        provided as the argument, then existing binding will be