Add m-esr52 at 52.6.0

1 files changed, 1907 insertions, 0 deletions

diff --git a/dom/base/Element.h b/dom/base/Element.h
new file mode 100644
index 000000000..5d878df60
--- /dev/null
+++ b/dom/base/Element.h
@@ -0,0 +1,1907 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+/*
+ * Base class for all element classes; this provides an implementation
+ * of DOM Core's nsIDOMElement, implements nsIContent, provides
+ * utility methods for subclasses, and so forth.
+ */
+
+#ifndef mozilla_dom_Element_h__
+#define mozilla_dom_Element_h__
+
+#include "mozilla/dom/FragmentOrElement.h" // for base class
+#include "nsChangeHint.h"                  // for enum
+#include "mozilla/EventStates.h"           // for member
+#include "mozilla/dom/DirectionalityUtils.h"
+#include "nsIDOMElement.h"
+#include "nsILinkHandler.h"
+#include "nsINodeList.h"
+#include "nsNodeUtils.h"
+#include "nsAttrAndChildArray.h"
+#include "mozFlushType.h"
+#include "nsDOMAttributeMap.h"
+#include "nsPresContext.h"
+#include "mozilla/CORSMode.h"
+#include "mozilla/Attributes.h"
+#include "nsIScrollableFrame.h"
+#include "mozilla/dom/Attr.h"
+#include "nsISMILAttr.h"
+#include "mozilla/dom/DOMRect.h"
+#include "nsAttrValue.h"
+#include "mozilla/EventForwards.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/DOMTokenListSupportedTokens.h"
+#include "mozilla/dom/WindowBinding.h"
+#include "mozilla/dom/ElementBinding.h"
+#include "mozilla/dom/Nullable.h"
+#include "Units.h"
+#include "DOMIntersectionObserver.h"
+
+class nsIFrame;
+class nsIDOMMozNamedAttrMap;
+class nsIURI;
+class nsIScrollableFrame;
+class nsAttrValueOrString;
+class nsContentList;
+class nsDOMTokenList;
+struct nsRect;
+class nsFocusManager;
+class nsGlobalWindow;
+class nsICSSDeclaration;
+class nsISMILAttr;
+class nsDocument;
+class nsDOMStringMap;
+
+namespace mozilla {
+class DeclarationBlock;
+namespace dom {
+  struct AnimationFilter;
+  struct ScrollIntoViewOptions;
+  struct ScrollToOptions;
+  class DOMIntersectionObserver;
+  class ElementOrCSSPseudoElement;
+  class UnrestrictedDoubleOrKeyframeAnimationOptions;
+} // namespace dom
+} // namespace mozilla
+
+
+already_AddRefed<nsContentList>
+NS_GetContentList(nsINode* aRootNode,
+                  int32_t  aMatchNameSpaceId,
+                  const nsAString& aTagname);
+
+#define ELEMENT_FLAG_BIT(n_) NODE_FLAG_BIT(NODE_TYPE_SPECIFIC_BITS_OFFSET + (n_))
+
+// Element-specific flags
+enum {
+  // Set if the element has a pending style change.
+  ELEMENT_HAS_PENDING_RESTYLE =                 NODE_SHARED_RESTYLE_BIT_1,
+
+  // Set if the element is a potential restyle root (that is, has a style
+  // change pending _and_ that style change will attempt to restyle
+  // descendants).
+  ELEMENT_IS_POTENTIAL_RESTYLE_ROOT =           NODE_SHARED_RESTYLE_BIT_2,
+
+  // Set if the element has a pending animation-only style change as
+  // part of an animation-only style update (where we update styles from
+  // animation to the current refresh tick, but leave everything else as
+  // it was).
+  ELEMENT_HAS_PENDING_ANIMATION_ONLY_RESTYLE =  ELEMENT_FLAG_BIT(0),
+
+  // Set if the element is a potential animation-only restyle root (that
+  // is, has an animation-only style change pending _and_ that style
+  // change will attempt to restyle descendants).
+  ELEMENT_IS_POTENTIAL_ANIMATION_ONLY_RESTYLE_ROOT = ELEMENT_FLAG_BIT(1),
+
+  // Set if this element has a pending restyle with an eRestyle_SomeDescendants
+  // restyle hint.
+  ELEMENT_IS_CONDITIONAL_RESTYLE_ANCESTOR = ELEMENT_FLAG_BIT(2),
+
+  // Just the HAS_PENDING bits, for convenience
+  ELEMENT_PENDING_RESTYLE_FLAGS =
+    ELEMENT_HAS_PENDING_RESTYLE |
+    ELEMENT_HAS_PENDING_ANIMATION_ONLY_RESTYLE,
+
+  // Just the IS_POTENTIAL bits, for convenience
+  ELEMENT_POTENTIAL_RESTYLE_ROOT_FLAGS =
+    ELEMENT_IS_POTENTIAL_RESTYLE_ROOT |
+    ELEMENT_IS_POTENTIAL_ANIMATION_ONLY_RESTYLE_ROOT,
+
+  // All of the restyle bits together, for convenience.
+  ELEMENT_ALL_RESTYLE_FLAGS = ELEMENT_PENDING_RESTYLE_FLAGS |
+                              ELEMENT_POTENTIAL_RESTYLE_ROOT_FLAGS |
+                              ELEMENT_IS_CONDITIONAL_RESTYLE_ANCESTOR,
+
+  // Set if this element is marked as 'scrollgrab' (see bug 912666)
+  ELEMENT_HAS_SCROLLGRAB = ELEMENT_FLAG_BIT(3),
+
+  // Remaining bits are for subclasses
+  ELEMENT_TYPE_SPECIFIC_BITS_OFFSET = NODE_TYPE_SPECIFIC_BITS_OFFSET + 4
+};
+
+#undef ELEMENT_FLAG_BIT
+
+// Make sure we have space for our bits
+ASSERT_NODE_FLAGS_SPACE(ELEMENT_TYPE_SPECIFIC_BITS_OFFSET);
+
+namespace mozilla {
+enum class CSSPseudoElementType : uint8_t;
+class EventChainPostVisitor;
+class EventChainPreVisitor;
+class EventChainVisitor;
+class EventListenerManager;
+class EventStateManager;
+
+namespace dom {
+
+class Animation;
+class CustomElementRegistry;
+class Link;
+class DOMRect;
+class DOMRectList;
+class DestinationInsertionPointList;
+class Grid;
+
+// IID for the dom::Element interface
+#define NS_ELEMENT_IID \
+{ 0xc67ed254, 0xfd3b, 0x4b10, \
+  { 0x96, 0xa2, 0xc5, 0x8b, 0x7b, 0x64, 0x97, 0xd1 } }
+
+class Element : public FragmentOrElement
+{
+public:
+#ifdef MOZILLA_INTERNAL_API
+  explicit Element(already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo) :
+    FragmentOrElement(aNodeInfo),
+    mState(NS_EVENT_STATE_MOZ_READONLY)
+  {
+    MOZ_ASSERT(mNodeInfo->NodeType() == nsIDOMNode::ELEMENT_NODE,
+               "Bad NodeType in aNodeInfo");
+    SetIsElement();
+  }
+#endif // MOZILLA_INTERNAL_API
+
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_ELEMENT_IID)
+
+  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
+
+  /**
+   * Method to get the full state of this element.  See mozilla/EventStates.h
+   * for the possible bits that could be set here.
+   */
+  EventStates State() const
+  {
+    // mState is maintained by having whoever might have changed it
+    // call UpdateState() or one of the other mState mutators.
+    return mState;
+  }
+
+  /**
+   * Ask this element to update its state.  If aNotify is false, then
+   * state change notifications will not be dispatched; in that
+   * situation it is the caller's responsibility to dispatch them.
+   *
+   * In general, aNotify should only be false if we're guaranteed that
+   * the element can't have a frame no matter what its style is
+   * (e.g. if we're in the middle of adding it to the document or
+   * removing it from the document).
+   */
+  void UpdateState(bool aNotify);
+
+  /**
+   * Method to update mState with link state information.  This does not notify.
+   */
+  void UpdateLinkState(EventStates aState);
+
+  virtual int32_t TabIndexDefault()
+  {
+    return -1;
+  }
+
+  /**
+   * Get tabIndex of this element. If not found, return TabIndexDefault.
+   */
+  int32_t TabIndex();
+
+  /**
+   * Set tabIndex value to this element.
+   */
+  void SetTabIndex(int32_t aTabIndex, mozilla::ErrorResult& aError);
+
+  /**
+   * Make focus on this element.
+   */
+  virtual void Focus(mozilla::ErrorResult& aError);
+
+  /**
+   * Show blur and clear focus.
+   */
+  virtual void Blur(mozilla::ErrorResult& aError);
+
+  /**
+   * The style state of this element. This is the real state of the element
+   * with any style locks applied for pseudo-class inspecting.
+   */
+  EventStates StyleState() const
+  {
+    if (!HasLockedStyleStates()) {
+      return mState;
+    }
+    return StyleStateFromLocks();
+  }
+
+  /**
+   * The style state locks applied to this element.
+   */
+  EventStates LockedStyleStates() const;
+
+  /**
+   * Add a style state lock on this element.
+   */
+  void LockStyleStates(EventStates aStates);
+
+  /**
+   * Remove a style state lock on this element.
+   */
+  void UnlockStyleStates(EventStates aStates);
+
+  /**
+   * Clear all style state locks on this element.
+   */
+  void ClearStyleStateLocks();
+
+  /**
+   * Get the inline style declaration, if any, for this element.
+   */
+  virtual DeclarationBlock* GetInlineStyleDeclaration();
+
+  /**
+   * Set the inline style declaration for this element. This will send
+   * an appropriate AttributeChanged notification if aNotify is true.
+   */
+  virtual nsresult SetInlineStyleDeclaration(DeclarationBlock* aDeclaration,
+                                             const nsAString* aSerialized,
+                                             bool aNotify);
+
+  /**
+   * Get the SMIL override style declaration for this element. If the
+   * rule hasn't been created, this method simply returns null.
+   */
+  virtual DeclarationBlock* GetSMILOverrideStyleDeclaration();
+
+  /**
+   * Set the SMIL override style declaration for this element. If
+   * aNotify is true, this method will notify the document's pres
+   * context, so that the style changes will be noticed.
+   */
+  virtual nsresult SetSMILOverrideStyleDeclaration(
+    DeclarationBlock* aDeclaration, bool aNotify);
+
+  /**
+   * Returns a new nsISMILAttr that allows the caller to animate the given
+   * attribute on this element.
+   *
+   * The CALLER OWNS the result and is responsible for deleting it.
+   */
+  virtual nsISMILAttr* GetAnimatedAttr(int32_t aNamespaceID, nsIAtom* aName)
+  {
+    return nullptr;
+  }
+
+  /**
+   * Get the SMIL override style for this element. This is a style declaration
+   * that is applied *after* the inline style, and it can be used e.g. to store
+   * animated style values.
+   *
+   * Note: This method is analogous to the 'GetStyle' method in
+   * nsGenericHTMLElement and nsStyledElement.
+   */
+  virtual nsICSSDeclaration* GetSMILOverrideStyle();
+
+  /**
+   * Returns if the element is labelable as per HTML specification.
+   */
+  virtual bool IsLabelable() const;
+
+  /**
+   * Returns if the element is interactive content as per HTML specification.
+   */
+  virtual bool IsInteractiveHTMLContent(bool aIgnoreTabindex) const;
+
+  /**
+   * Is the attribute named stored in the mapped attributes?
+   *
+   * // XXXbz we use this method in HasAttributeDependentStyle, so svg
+   *    returns true here even though it stores nothing in the mapped
+   *    attributes.
+   */
+  NS_IMETHOD_(bool) IsAttributeMapped(const nsIAtom* aAttribute) const;
+
+  /**
+   * Get a hint that tells the style system what to do when
+   * an attribute on this node changes, if something needs to happen
+   * in response to the change *other* than the result of what is
+   * mapped into style data via any type of style rule.
+   */
+  virtual nsChangeHint GetAttributeChangeHint(const nsIAtom* aAttribute,
+                                              int32_t aModType) const;
+
+  inline Directionality GetDirectionality() const {
+    if (HasFlag(NODE_HAS_DIRECTION_RTL)) {
+      return eDir_RTL;
+    }
+
+    if (HasFlag(NODE_HAS_DIRECTION_LTR)) {
+      return eDir_LTR;
+    }
+
+    return eDir_NotSet;
+  }
+
+  inline void SetDirectionality(Directionality aDir, bool aNotify) {
+    UnsetFlags(NODE_ALL_DIRECTION_FLAGS);
+    if (!aNotify) {
+      RemoveStatesSilently(DIRECTION_STATES);
+    }
+
+    switch (aDir) {
+      case (eDir_RTL):
+        SetFlags(NODE_HAS_DIRECTION_RTL);
+        if (!aNotify) {
+          AddStatesSilently(NS_EVENT_STATE_RTL);
+        }
+        break;
+
+      case(eDir_LTR):
+        SetFlags(NODE_HAS_DIRECTION_LTR);
+        if (!aNotify) {
+          AddStatesSilently(NS_EVENT_STATE_LTR);
+        }
+        break;
+
+      default:
+        break;
+    }
+
+    /*
+     * Only call UpdateState if we need to notify, because we call
+     * SetDirectionality for every element, and UpdateState is very very slow
+     * for some elements.
+     */
+    if (aNotify) {
+      UpdateState(true);
+    }
+  }
+
+  bool GetBindingURL(nsIDocument *aDocument, css::URLValue **aResult);
+
+  // The bdi element defaults to dir=auto if it has no dir attribute set.
+  // Other elements will only have dir=auto if they have an explicit dir=auto,
+  // which will mean that HasValidDir() returns true but HasFixedDir() returns
+  // false
+  inline bool HasDirAuto() const {
+    return (!HasFixedDir() &&
+            (HasValidDir() || IsHTMLElement(nsGkAtoms::bdi)));
+  }
+
+  Directionality GetComputedDirectionality() const;
+
+protected:
+  /**
+   * Method to get the _intrinsic_ content state of this element.  This is the
+   * state that is independent of the element's presentation.  To get the full
+   * content state, use State().  See mozilla/EventStates.h for
+   * the possible bits that could be set here.
+   */
+  virtual EventStates IntrinsicState() const;
+
+  /**
+   * Method to add state bits.  This should be called from subclass
+   * constructors to set up our event state correctly at construction
+   * time and other places where we don't want to notify a state
+   * change.
+   */
+  void AddStatesSilently(EventStates aStates)
+  {
+    mState |= aStates;
+  }
+
+  /**
+   * Method to remove state bits.  This should be called from subclass
+   * constructors to set up our event state correctly at construction
+   * time and other places where we don't want to notify a state
+   * change.
+   */
+  void RemoveStatesSilently(EventStates aStates)
+  {
+    mState &= ~aStates;
+  }
+
+private:
+  // Need to allow the ESM, nsGlobalWindow, and the focus manager to
+  // set our state
+  friend class mozilla::EventStateManager;
+  friend class ::nsGlobalWindow;
+  friend class ::nsFocusManager;
+
+  // Allow CusomtElementRegistry to call AddStates.
+  friend class CustomElementRegistry;
+
+  // Also need to allow Link to call UpdateLinkState.
+  friend class Link;
+
+  void NotifyStateChange(EventStates aStates);
+
+  void NotifyStyleStateChange(EventStates aStates);
+
+  // Style state computed from element's state and style locks.
+  EventStates StyleStateFromLocks() const;
+
+protected:
+  // Methods for the ESM to manage state bits.  These will handle
+  // setting up script blockers when they notify, so no need to do it
+  // in the callers unless desired.
+  virtual void AddStates(EventStates aStates)
+  {
+    NS_PRECONDITION(!aStates.HasAtLeastOneOfStates(INTRINSIC_STATES),
+                    "Should only be adding ESM-managed states here");
+    AddStatesSilently(aStates);
+    NotifyStateChange(aStates);
+  }
+  virtual void RemoveStates(EventStates aStates)
+  {
+    NS_PRECONDITION(!aStates.HasAtLeastOneOfStates(INTRINSIC_STATES),
+                    "Should only be removing ESM-managed states here");
+    RemoveStatesSilently(aStates);
+    NotifyStateChange(aStates);
+  }
+public:
+  virtual void UpdateEditableState(bool aNotify) override;
+
+  virtual nsresult BindToTree(nsIDocument* aDocument, nsIContent* aParent,
+                              nsIContent* aBindingParent,
+                              bool aCompileEventHandlers) override;
+  virtual void UnbindFromTree(bool aDeep = true,
+                              bool aNullParent = true) override;
+
+  /**
+   * Normalizes an attribute name and returns it as a nodeinfo if an attribute
+   * with that name exists. This method is intended for character case
+   * conversion if the content object is case insensitive (e.g. HTML). Returns
+   * the nodeinfo of the attribute with the specified name if one exists or
+   * null otherwise.
+   *
+   * @param aStr the unparsed attribute string
+   * @return the node info. May be nullptr.
+   */
+  already_AddRefed<mozilla::dom::NodeInfo>
+  GetExistingAttrNameFromQName(const nsAString& aStr) const;
+
+  nsresult SetAttr(int32_t aNameSpaceID, nsIAtom* aName,
+                   const nsAString& aValue, bool aNotify)
+  {
+    return SetAttr(aNameSpaceID, aName, nullptr, aValue, aNotify);
+  }
+
+  /**
+   * Helper for SetAttr/SetParsedAttr. This method will return true if aNotify
+   * is true or there are mutation listeners that must be triggered, the
+   * attribute is currently set, and the new value that is about to be set is
+   * different to the current value. As a perf optimization the new and old
+   * values will not actually be compared if we aren't notifying and we don't
+   * have mutation listeners (in which case it's cheap to just return false
+   * and let the caller go ahead and set the value).
+   * @param aOldValue Set to the old value of the attribute, but only if there
+   *   are event listeners. If set, the type of aOldValue will be either
+   *   nsAttrValue::eString or nsAttrValue::eAtom.
+   * @param aModType Set to nsIDOMMutationEvent::MODIFICATION or to
+   *   nsIDOMMutationEvent::ADDITION, but only if this helper returns true
+   * @param aHasListeners Set to true if there are mutation event listeners
+   *   listening for NS_EVENT_BITS_MUTATION_ATTRMODIFIED
+   */
+  bool MaybeCheckSameAttrVal(int32_t aNamespaceID, nsIAtom* aName,
+                             nsIAtom* aPrefix,
+                             const nsAttrValueOrString& aValue,
+                             bool aNotify, nsAttrValue& aOldValue,
+                             uint8_t* aModType, bool* aHasListeners);
+
+  bool OnlyNotifySameValueSet(int32_t aNamespaceID, nsIAtom* aName,
+                              nsIAtom* aPrefix,
+                              const nsAttrValueOrString& aValue,
+                              bool aNotify, nsAttrValue& aOldValue,
+                              uint8_t* aModType, bool* aHasListeners);
+
+  virtual nsresult SetAttr(int32_t aNameSpaceID, nsIAtom* aName, nsIAtom* aPrefix,
+                           const nsAString& aValue, bool aNotify) override;
+  // aParsedValue receives the old value of the attribute. That's useful if
+  // either the input or output value of aParsedValue is StoresOwnData.
+  nsresult SetParsedAttr(int32_t aNameSpaceID, nsIAtom* aName, nsIAtom* aPrefix,
+                         nsAttrValue& aParsedValue, bool aNotify);
+  // GetAttr is not inlined on purpose, to keep down codesize from all
+  // the inlined nsAttrValue bits for C++ callers.
+  bool GetAttr(int32_t aNameSpaceID, nsIAtom* aName,
+               nsAString& aResult) const;
+  inline bool HasAttr(int32_t aNameSpaceID, nsIAtom* aName) const;
+  // aCaseSensitive == eIgnoreCaase means ASCII case-insensitive matching.
+  inline bool AttrValueIs(int32_t aNameSpaceID, nsIAtom* aName,
+                          const nsAString& aValue,
+                          nsCaseTreatment aCaseSensitive) const;
+  inline bool AttrValueIs(int32_t aNameSpaceID, nsIAtom* aName,
+                          nsIAtom* aValue,
+                          nsCaseTreatment aCaseSensitive) const;
+  virtual int32_t FindAttrValueIn(int32_t aNameSpaceID,
+                                  nsIAtom* aName,
+                                  AttrValuesArray* aValues,
+                                  nsCaseTreatment aCaseSensitive) const override;
+  virtual nsresult UnsetAttr(int32_t aNameSpaceID, nsIAtom* aAttribute,
+                             bool aNotify) override;
+  virtual const nsAttrName* GetAttrNameAt(uint32_t aIndex) const override;
+  virtual BorrowedAttrInfo GetAttrInfoAt(uint32_t aIndex) const override;
+  virtual uint32_t GetAttrCount() const override;
+  virtual bool IsNodeOfType(uint32_t aFlags) const override;
+
+#ifdef DEBUG
+  virtual void List(FILE* out = stdout, int32_t aIndent = 0) const override
+  {
+    List(out, aIndent, EmptyCString());
+  }
+  virtual void DumpContent(FILE* out, int32_t aIndent, bool aDumpAll) const override;
+  void List(FILE* out, int32_t aIndent, const nsCString& aPrefix) const;
+  void ListAttributes(FILE* out) const;
+#endif
+
+  void Describe(nsAString& aOutDescription) const override;
+
+  /*
+   * Attribute Mapping Helpers
+   */
+  struct MappedAttributeEntry {
+    nsIAtom** attribute;
+  };
+
+  /**
+   * A common method where you can just pass in a list of maps to check
+   * for attribute dependence. Most implementations of
+   * IsAttributeMapped should use this function as a default
+   * handler.
+   */
+  template<size_t N>
+  static bool
+  FindAttributeDependence(const nsIAtom* aAttribute,
+                          const MappedAttributeEntry* const (&aMaps)[N])
+  {
+    return FindAttributeDependence(aAttribute, aMaps, N);
+  }
+
+  static nsIAtom*** HTMLSVGPropertiesToTraverseAndUnlink();
+
+private:
+  void DescribeAttribute(uint32_t index, nsAString& aOutDescription) const;
+
+  static bool
+  FindAttributeDependence(const nsIAtom* aAttribute,
+                          const MappedAttributeEntry* const aMaps[],
+                          uint32_t aMapCount);
+
+protected:
+  inline bool GetAttr(int32_t aNameSpaceID, nsIAtom* aName,
+                      DOMString& aResult) const
+  {
+    NS_ASSERTION(nullptr != aName, "must have attribute name");
+    NS_ASSERTION(aNameSpaceID != kNameSpaceID_Unknown,
+                 "must have a real namespace ID!");
+    MOZ_ASSERT(aResult.HasStringBuffer() && aResult.StringBufferLength() == 0,
+               "Should have empty string coming in");
+    const nsAttrValue* val = mAttrsAndChildren.GetAttr(aName, aNameSpaceID);
+    if (val) {
+      val->ToString(aResult);
+      return true;
+    }
+    // else DOMString comes pre-emptied.
+    return false;
+  }
+
+public:
+  bool HasAttrs() const { return mAttrsAndChildren.HasAttrs(); }
+
+  inline bool GetAttr(const nsAString& aName, DOMString& aResult) const
+  {
+    MOZ_ASSERT(aResult.HasStringBuffer() && aResult.StringBufferLength() == 0,
+               "Should have empty string coming in");
+    const nsAttrValue* val = mAttrsAndChildren.GetAttr(aName);
+    if (val) {
+      val->ToString(aResult);
+      return true;
+    }
+    // else DOMString comes pre-emptied.
+    return false;
+  }
+
+  void GetTagName(nsAString& aTagName) const
+  {
+    aTagName = NodeName();
+  }
+  void GetId(nsAString& aId) const
+  {
+    GetAttr(kNameSpaceID_None, nsGkAtoms::id, aId);
+  }
+  void GetId(DOMString& aId) const
+  {
+    GetAttr(kNameSpaceID_None, nsGkAtoms::id, aId);
+  }
+  void SetId(const nsAString& aId)
+  {
+    SetAttr(kNameSpaceID_None, nsGkAtoms::id, aId, true);
+  }
+  void GetClassName(nsAString& aClassName)
+  {
+    GetAttr(kNameSpaceID_None, nsGkAtoms::_class, aClassName);
+  }
+  void GetClassName(DOMString& aClassName)
+  {
+    GetAttr(kNameSpaceID_None, nsGkAtoms::_class, aClassName);
+  }
+  void SetClassName(const nsAString& aClassName)
+  {
+    SetAttr(kNameSpaceID_None, nsGkAtoms::_class, aClassName, true);
+  }
+
+  nsDOMTokenList* ClassList();
+  nsDOMAttributeMap* Attributes()
+  {
+    nsDOMSlots* slots = DOMSlots();
+    if (!slots->mAttributeMap) {
+      slots->mAttributeMap = new nsDOMAttributeMap(this);
+    }
+
+    return slots->mAttributeMap;
+  }
+
+  void GetAttributeNames(nsTArray<nsString>& aResult);
+
+  void GetAttribute(const nsAString& aName, nsString& aReturn)
+  {
+    DOMString str;
+    GetAttribute(aName, str);
+    str.ToString(aReturn);
+  }
+
+  void GetAttribute(const nsAString& aName, DOMString& aReturn);
+  void GetAttributeNS(const nsAString& aNamespaceURI,
+                      const nsAString& aLocalName,
+                      nsAString& aReturn);
+  void SetAttribute(const nsAString& aName, const nsAString& aValue,
+                    ErrorResult& aError);
+  void SetAttributeNS(const nsAString& aNamespaceURI,
+                      const nsAString& aLocalName,
+                      const nsAString& aValue,
+                      ErrorResult& aError);
+  void RemoveAttribute(const nsAString& aName,
+                       ErrorResult& aError);
+  void RemoveAttributeNS(const nsAString& aNamespaceURI,
+                         const nsAString& aLocalName,
+                         ErrorResult& aError);
+  bool HasAttribute(const nsAString& aName) const
+  {
+    return InternalGetAttrNameFromQName(aName) != nullptr;
+  }
+  bool HasAttributeNS(const nsAString& aNamespaceURI,
+                      const nsAString& aLocalName) const;
+  bool HasAttributes() const
+  {
+    return HasAttrs();
+  }
+  Element* Closest(const nsAString& aSelector,
+                   ErrorResult& aResult);
+  bool Matches(const nsAString& aSelector,
+               ErrorResult& aError);
+  already_AddRefed<nsIHTMLCollection>
+    GetElementsByTagName(const nsAString& aQualifiedName);
+  already_AddRefed<nsIHTMLCollection>
+    GetElementsByTagNameNS(const nsAString& aNamespaceURI,
+                           const nsAString& aLocalName,
+                           ErrorResult& aError);
+  already_AddRefed<nsIHTMLCollection>
+    GetElementsByClassName(const nsAString& aClassNames);
+
+private:
+  /**
+   * Implement the algorithm specified at
+   * https://dom.spec.whatwg.org/#insert-adjacent for both
+   * |insertAdjacentElement()| and |insertAdjacentText()| APIs.
+   */
+  nsINode* InsertAdjacent(const nsAString& aWhere,
+                          nsINode* aNode,
+                          ErrorResult& aError);
+
+public:
+  Element* InsertAdjacentElement(const nsAString& aWhere,
+                                 Element& aElement,
+                                 ErrorResult& aError);
+
+  void InsertAdjacentText(const nsAString& aWhere,
+                          const nsAString& aData,
+                          ErrorResult& aError);
+
+  void SetPointerCapture(int32_t aPointerId, ErrorResult& aError)
+  {
+    bool activeState = false;
+    if (!nsIPresShell::GetPointerInfo(aPointerId, activeState)) {
+      aError.Throw(NS_ERROR_DOM_INVALID_POINTER_ERR);
+      return;
+    }
+    if (!IsInUncomposedDoc()) {
+      aError.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+      return;
+    }
+    if (!activeState) {
+      return;
+    }
+    nsIPresShell::SetPointerCapturingContent(aPointerId, this);
+  }
+  void ReleasePointerCapture(int32_t aPointerId, ErrorResult& aError)
+  {
+    bool activeState = false;
+    if (!nsIPresShell::GetPointerInfo(aPointerId, activeState)) {
+      aError.Throw(NS_ERROR_DOM_INVALID_POINTER_ERR);
+      return;
+    }
+    if (HasPointerCapture(aPointerId)) {
+      nsIPresShell::ReleasePointerCapturingContent(aPointerId);
+    }
+  }
+  bool HasPointerCapture(long aPointerId)
+  {
+    nsIPresShell::PointerCaptureInfo* pointerCaptureInfo =
+      nsIPresShell::GetPointerCaptureInfo(aPointerId);
+    if (pointerCaptureInfo && pointerCaptureInfo->mPendingContent == this) {
+      return true;
+    }
+    return false;
+  }
+  void SetCapture(bool aRetargetToElement)
+  {
+    // If there is already an active capture, ignore this request. This would
+    // occur if a splitter, frame resizer, etc had already captured and we don't
+    // want to override those.
+    if (!nsIPresShell::GetCapturingContent()) {
+      nsIPresShell::SetCapturingContent(this, CAPTURE_PREVENTDRAG |
+        (aRetargetToElement ? CAPTURE_RETARGETTOELEMENT : 0));
+    }
+  }
+  void ReleaseCapture()
+  {
+    if (nsIPresShell::GetCapturingContent() == this) {
+      nsIPresShell::SetCapturingContent(nullptr, 0);
+    }
+  }
+
+  void RequestFullscreen(ErrorResult& aError);
+  void RequestPointerLock();
+  Attr* GetAttributeNode(const nsAString& aName);
+  already_AddRefed<Attr> SetAttributeNode(Attr& aNewAttr,
+                                          ErrorResult& aError);
+  already_AddRefed<Attr> RemoveAttributeNode(Attr& aOldAttr,
+                                             ErrorResult& aError);
+  Attr* GetAttributeNodeNS(const nsAString& aNamespaceURI,
+                           const nsAString& aLocalName);
+  already_AddRefed<Attr> SetAttributeNodeNS(Attr& aNewAttr,
+                                            ErrorResult& aError);
+
+  already_AddRefed<DOMRectList> GetClientRects();
+  already_AddRefed<DOMRect> GetBoundingClientRect();
+
+  already_AddRefed<ShadowRoot> CreateShadowRoot(ErrorResult& aError);
+  already_AddRefed<DestinationInsertionPointList> GetDestinationInsertionPoints();
+
+  ShadowRoot *FastGetShadowRoot() const
+  {
+    nsDOMSlots* slots = GetExistingDOMSlots();
+    return slots ? slots->mShadowRoot.get() : nullptr;
+  }
+
+  void ScrollIntoView();
+  void ScrollIntoView(bool aTop);
+  void ScrollIntoView(const ScrollIntoViewOptions &aOptions);
+  void Scroll(double aXScroll, double aYScroll);
+  void Scroll(const ScrollToOptions& aOptions);
+  void ScrollTo(double aXScroll, double aYScroll);
+  void ScrollTo(const ScrollToOptions& aOptions);
+  void ScrollBy(double aXScrollDif, double aYScrollDif);
+  void ScrollBy(const ScrollToOptions& aOptions);
+  /* Scrolls without flushing the layout.
+   * aDx is the x offset, aDy the y offset in CSS pixels.
+   * Returns true if we actually scrolled.
+   */
+  bool ScrollByNoFlush(int32_t aDx, int32_t aDy);
+  int32_t ScrollTop();
+  void SetScrollTop(int32_t aScrollTop);
+  int32_t ScrollLeft();
+  void SetScrollLeft(int32_t aScrollLeft);
+  int32_t ScrollWidth();
+  int32_t ScrollHeight();
+  void MozScrollSnap();
+  int32_t ClientTop()
+  {
+    return nsPresContext::AppUnitsToIntCSSPixels(GetClientAreaRect().y);
+  }
+  int32_t ClientLeft()
+  {
+    return nsPresContext::AppUnitsToIntCSSPixels(GetClientAreaRect().x);
+  }
+  int32_t ClientWidth()
+  {
+    return nsPresContext::AppUnitsToIntCSSPixels(GetClientAreaRect().width);
+  }
+  int32_t ClientHeight()
+  {
+    return nsPresContext::AppUnitsToIntCSSPixels(GetClientAreaRect().height);
+  }
+  int32_t ScrollTopMin()
+  {
+    nsIScrollableFrame* sf = GetScrollFrame();
+    return sf ?
+           nsPresContext::AppUnitsToIntCSSPixels(sf->GetScrollRange().y) : 0;
+  }
+  int32_t ScrollTopMax()
+  {
+    nsIScrollableFrame* sf = GetScrollFrame();
+    return sf ?
+           nsPresContext::AppUnitsToIntCSSPixels(sf->GetScrollRange().YMost()) :
+           0;
+  }
+  int32_t ScrollLeftMin()
+  {
+    nsIScrollableFrame* sf = GetScrollFrame();
+    return sf ?
+           nsPresContext::AppUnitsToIntCSSPixels(sf->GetScrollRange().x) : 0;
+  }
+  int32_t ScrollLeftMax()
+  {
+    nsIScrollableFrame* sf = GetScrollFrame();
+    return sf ?
+           nsPresContext::AppUnitsToIntCSSPixels(sf->GetScrollRange().XMost()) :
+           0;
+  }
+
+  void GetGridFragments(nsTArray<RefPtr<Grid>>& aResult);
+
+  already_AddRefed<Animation>
+  Animate(JSContext* aContext,
+          JS::Handle<JSObject*> aKeyframes,
+          const UnrestrictedDoubleOrKeyframeAnimationOptions& aOptions,
+          ErrorResult& aError);
+
+  // A helper method that factors out the common functionality needed by
+  // Element::Animate and CSSPseudoElement::Animate
+  static already_AddRefed<Animation>
+  Animate(const Nullable<ElementOrCSSPseudoElement>& aTarget,
+          JSContext* aContext,
+          JS::Handle<JSObject*> aKeyframes,
+          const UnrestrictedDoubleOrKeyframeAnimationOptions& aOptions,
+          ErrorResult& aError);
+
+  // Note: GetAnimations will flush style while GetAnimationsUnsorted won't.
+  // Callers must keep this element alive because flushing style may destroy
+  // this element.
+  void GetAnimations(const AnimationFilter& filter,
+                     nsTArray<RefPtr<Animation>>& aAnimations);
+  static void GetAnimationsUnsorted(Element* aElement,
+                                    CSSPseudoElementType aPseudoType,
+                                    nsTArray<RefPtr<Animation>>& aAnimations);
+
+  NS_IMETHOD GetInnerHTML(nsAString& aInnerHTML);
+  virtual void SetInnerHTML(const nsAString& aInnerHTML, ErrorResult& aError);
+  void GetOuterHTML(nsAString& aOuterHTML);
+  void SetOuterHTML(const nsAString& aOuterHTML, ErrorResult& aError);
+  void InsertAdjacentHTML(const nsAString& aPosition, const nsAString& aText,
+                          ErrorResult& aError);
+
+  //----------------------------------------
+
+  /**
+   * Add a script event listener with the given event handler name
+   * (like onclick) and with the value as JS
+   * @param aEventName the event listener name
+   * @param aValue the JS to attach
+   * @param aDefer indicates if deferred execution is allowed
+   */
+  nsresult SetEventHandler(nsIAtom* aEventName,
+                           const nsAString& aValue,
+                           bool aDefer = true);
+
+  /**
+   * Do whatever needs to be done when the mouse leaves a link
+   */
+  nsresult LeaveLink(nsPresContext* aPresContext);
+
+  static bool ShouldBlur(nsIContent *aContent);
+
+  /**
+   * Method to create and dispatch a left-click event loosely based on
+   * aSourceEvent. If aFullDispatch is true, the event will be dispatched
+   * through the full dispatching of the presshell of the aPresContext; if it's
+   * false the event will be dispatched only as a DOM event.
+   * If aPresContext is nullptr, this does nothing.
+   *
+   * @param aFlags      Extra flags for the dispatching event.  The true flags
+   *                    will be respected.
+   */
+  static nsresult DispatchClickEvent(nsPresContext* aPresContext,
+                                     WidgetInputEvent* aSourceEvent,
+                                     nsIContent* aTarget,
+                                     bool aFullDispatch,
+                                     const EventFlags* aFlags,
+                                     nsEventStatus* aStatus);
+
+  /**
+   * Method to dispatch aEvent to aTarget. If aFullDispatch is true, the event
+   * will be dispatched through the full dispatching of the presshell of the
+   * aPresContext; if it's false the event will be dispatched only as a DOM
+   * event.
+   * If aPresContext is nullptr, this does nothing.
+   */
+  using nsIContent::DispatchEvent;
+  static nsresult DispatchEvent(nsPresContext* aPresContext,
+                                WidgetEvent* aEvent,
+                                nsIContent* aTarget,
+                                bool aFullDispatch,
+                                nsEventStatus* aStatus);
+
+  /**
+   * Get the primary frame for this content with flushing
+   *
+   * @param aType the kind of flush to do, typically Flush_Frames or
+   *              Flush_Layout
+   * @return the primary frame
+   */
+  nsIFrame* GetPrimaryFrame(mozFlushType aType);
+  // Work around silly C++ name hiding stuff
+  nsIFrame* GetPrimaryFrame() const { return nsIContent::GetPrimaryFrame(); }
+
+  const nsAttrValue* GetParsedAttr(nsIAtom* aAttr) const
+  {
+    return mAttrsAndChildren.GetAttr(aAttr);
+  }
+
+  const nsAttrValue* GetParsedAttr(nsIAtom* aAttr, int32_t aNameSpaceID) const
+  {
+    return mAttrsAndChildren.GetAttr(aAttr, aNameSpaceID);
+  }
+
+  /**
+   * Returns the attribute map, if there is one.
+   *
+   * @return existing attribute map or nullptr.
+   */
+  nsDOMAttributeMap *GetAttributeMap()
+  {
+    nsDOMSlots *slots = GetExistingDOMSlots();
+
+    return slots ? slots->mAttributeMap.get() : nullptr;
+  }
+
+  virtual void RecompileScriptEventListeners()
+  {
+  }
+
+  /**
+   * Get the attr info for the given namespace ID and attribute name.  The
+   * namespace ID must not be kNameSpaceID_Unknown and the name must not be
+   * null.  Note that this can only return info on attributes that actually
+   * live on this element (and is only virtual to handle XUL prototypes).  That
+   * is, this should only be called from methods that only care about attrs
+   * that effectively live in mAttrsAndChildren.
+   */
+  virtual BorrowedAttrInfo GetAttrInfo(int32_t aNamespaceID, nsIAtom* aName) const;
+
+  virtual void NodeInfoChanged()
+  {
+  }
+
+  /**
+   * Parse a string into an nsAttrValue for a CORS attribute.  This
+   * never fails.  The resulting value is an enumerated value whose
+   * GetEnumValue() returns one of the above constants.
+   */
+  static void ParseCORSValue(const nsAString& aValue, nsAttrValue& aResult);
+
+  /**
+   * Return the CORS mode for a given string
+   */
+  static CORSMode StringToCORSMode(const nsAString& aValue);
+
+  /**
+   * Return the CORS mode for a given nsAttrValue (which may be null,
+   * but if not should have been parsed via ParseCORSValue).
+   */
+  static CORSMode AttrValueToCORSMode(const nsAttrValue* aValue);
+
+  // These are just used to implement nsIDOMElement using
+  // NS_FORWARD_NSIDOMELEMENT_TO_GENERIC and for quickstubs.
+  void
+    GetElementsByTagName(const nsAString& aQualifiedName,
+                         nsIDOMHTMLCollection** aResult);
+  nsresult
+    GetElementsByTagNameNS(const nsAString& aNamespaceURI,
+                           const nsAString& aLocalName,
+                           nsIDOMHTMLCollection** aResult);
+  nsresult
+    GetElementsByClassName(const nsAString& aClassNames,
+                           nsIDOMHTMLCollection** aResult);
+  void GetClassList(nsISupports** aClassList);
+
+  virtual JSObject* WrapObject(JSContext *aCx, JS::Handle<JSObject*> aGivenProto) final override;
+
+  nsINode* GetScopeChainParent() const override;
+
+  /**
+   * Locate an nsIEditor rooted at this content node, if there is one.
+   */
+  nsIEditor* GetEditorInternal();
+
+  /**
+   * Helper method for NS_IMPL_BOOL_ATTR macro.
+   * Gets value of boolean attribute. Only works for attributes in null
+   * namespace.
+   *
+   * @param aAttr    name of attribute.
+   * @param aValue   Boolean value of attribute.
+   */
+  bool GetBoolAttr(nsIAtom* aAttr) const
+  {
+    return HasAttr(kNameSpaceID_None, aAttr);
+  }
+
+  /**
+   * Helper method for NS_IMPL_BOOL_ATTR macro.
+   * Sets value of boolean attribute by removing attribute or setting it to
+   * the empty string. Only works for attributes in null namespace.
+   *
+   * @param aAttr    name of attribute.
+   * @param aValue   Boolean value of attribute.
+   */
+  nsresult SetBoolAttr(nsIAtom* aAttr, bool aValue);
+
+  /**
+   * Helper method for NS_IMPL_ENUM_ATTR_DEFAULT_VALUE.
+   * Gets the enum value string of an attribute and using a default value if
+   * the attribute is missing or the string is an invalid enum value.
+   *
+   * @param aType     the name of the attribute.
+   * @param aDefault  the default value if the attribute is missing or invalid.
+   * @param aResult   string corresponding to the value [out].
+   */
+  void GetEnumAttr(nsIAtom* aAttr,
+                   const char* aDefault,
+                   nsAString& aResult) const;
+
+  /**
+   * Helper method for NS_IMPL_ENUM_ATTR_DEFAULT_MISSING_INVALID_VALUES.
+   * Gets the enum value string of an attribute and using the default missing
+   * value if the attribute is missing or the default invalid value if the
+   * string is an invalid enum value.
+   *
+   * @param aType            the name of the attribute.
+   * @param aDefaultMissing  the default value if the attribute is missing.  If
+                             null and the attribute is missing, aResult will be
+                             set to the null DOMString; this only matters for
+                             cases in which we're reflecting a nullable string.
+   * @param aDefaultInvalid  the default value if the attribute is invalid.
+   * @param aResult          string corresponding to the value [out].
+   */
+  void GetEnumAttr(nsIAtom* aAttr,
+                   const char* aDefaultMissing,
+                   const char* aDefaultInvalid,
+                   nsAString& aResult) const;
+
+  /**
+   * Unset an attribute.
+   */
+  void UnsetAttr(nsIAtom* aAttr, ErrorResult& aError)
+  {
+    aError = UnsetAttr(kNameSpaceID_None, aAttr, true);
+  }
+
+  /**
+   * Set an attribute in the simplest way possible.
+   */
+  void SetAttr(nsIAtom* aAttr, const nsAString& aValue, ErrorResult& aError)
+  {
+    aError = SetAttr(kNameSpaceID_None, aAttr, aValue, true);
+  }
+
+  /**
+   * Set a content attribute via a reflecting nullable string IDL
+   * attribute (e.g. a CORS attribute).  If DOMStringIsNull(aValue),
+   * this will actually remove the content attribute.
+   */
+  void SetOrRemoveNullableStringAttr(nsIAtom* aName, const nsAString& aValue,
+                                     ErrorResult& aError);
+
+  /**
+   * Retrieve the ratio of font-size-inflated text font size to computed font
+   * size for this element. This will query the element for its primary frame,
+   * and then use this to get font size inflation information about the frame.
+   *
+   * @returns The font size inflation ratio (inflated font size to uninflated
+   *          font size) for the primary frame of this element. Returns 1.0
+   *          by default if font size inflation is not enabled. Returns -1
+   *          if the element does not have a primary frame.
+   *
+   * @note The font size inflation ratio that is returned is actually the
+   *       font size inflation data for the element's _primary frame_, not the
+   *       element itself, but for most purposes, this should be sufficient.
+   */
+  float FontSizeInflation();
+
+  net::ReferrerPolicy GetReferrerPolicyAsEnum();
+
+  /*
+   * Helpers for .dataset.  This is implemented on Element, though only some
+   * sorts of elements expose it to JS as a .dataset property
+   */
+  // Getter, to be called from bindings.
+  already_AddRefed<nsDOMStringMap> Dataset();
+  // Callback for destructor of dataset to ensure to null out our weak pointer
+  // to it.
+  void ClearDataset();
+
+  void RegisterIntersectionObserver(DOMIntersectionObserver* aObserver);
+  void UnregisterIntersectionObserver(DOMIntersectionObserver* aObserver);
+  bool UpdateIntersectionObservation(DOMIntersectionObserver* aObserver, int32_t threshold);
+
+protected:
+  /*
+   * Named-bools for use with SetAttrAndNotify to make call sites easier to
+   * read.
+   */
+  static const bool kFireMutationEvent           = true;
+  static const bool kDontFireMutationEvent       = false;
+  static const bool kNotifyDocumentObservers     = true;
+  static const bool kDontNotifyDocumentObservers = false;
+  static const bool kCallAfterSetAttr            = true;
+  static const bool kDontCallAfterSetAttr        = false;
+
+  /**
+   * Set attribute and (if needed) notify documentobservers and fire off
+   * mutation events.  This will send the AttributeChanged notification.
+   * Callers of this method are responsible for calling AttributeWillChange,
+   * since that needs to happen before the new attr value has been set, and
+   * in particular before it has been parsed.
+   *
+   * For the boolean parameters, consider using the named bools above to aid
+   * code readability.
+   *
+   * @param aNamespaceID  namespace of attribute
+   * @param aAttribute    local-name of attribute
+   * @param aPrefix       aPrefix of attribute
+   * @param aOldValue     The old value of the attribute to use as a fallback
+   *                      in the cases where the actual old value (i.e.
+   *                      its current value) is !StoresOwnData() --- in which
+   *                      case the current value is probably already useless.
+   *                      If the current value is StoresOwnData() (or absent),
+   *                      aOldValue will not be used.
+   * @param aParsedValue  parsed new value of attribute. Replaced by the
+   *                      old value of the attribute. This old value is only
+   *                      useful if either it or the new value is StoresOwnData.
+   * @param aModType      nsIDOMMutationEvent::MODIFICATION or ADDITION.  Only
+   *                      needed if aFireMutation or aNotify is true.
+   * @param aFireMutation should mutation-events be fired?
+   * @param aNotify       should we notify document-observers?
+   * @param aCallAfterSetAttr should we call AfterSetAttr?
+   */
+  nsresult SetAttrAndNotify(int32_t aNamespaceID,
+                            nsIAtom* aName,
+                            nsIAtom* aPrefix,
+                            const nsAttrValue& aOldValue,
+                            nsAttrValue& aParsedValue,
+                            uint8_t aModType,
+                            bool aFireMutation,
+                            bool aNotify,
+                            bool aCallAfterSetAttr);
+
+  /**
+   * Scroll to a new position using behavior evaluated from CSS and
+   * a CSSOM-View DOM method ScrollOptions dictionary.  The scrolling may
+   * be performed asynchronously or synchronously depending on the resolved
+   * scroll-behavior.
+   *
+   * @param aScroll       Destination of scroll, in CSS pixels
+   * @param aOptions      Dictionary of options to be evaluated
+   */
+  void Scroll(const CSSIntPoint& aScroll, const ScrollOptions& aOptions);
+
+  /**
+   * Convert an attribute string value to attribute type based on the type of
+   * attribute.  Called by SetAttr().  Note that at the moment we only do this
+   * for attributes in the null namespace (kNameSpaceID_None).
+   *
+   * @param aNamespaceID the namespace of the attribute to convert
+   * @param aAttribute the attribute to convert
+   * @param aValue the string value to convert
+   * @param aResult the nsAttrValue [OUT]
+   * @return true if the parsing was successful, false otherwise
+   */
+  virtual bool ParseAttribute(int32_t aNamespaceID,
+                                nsIAtom* aAttribute,
+                                const nsAString& aValue,
+                                nsAttrValue& aResult);
+
+  /**
+   * Try to set the attribute as a mapped attribute, if applicable.  This will
+   * only be called for attributes that are in the null namespace and only on
+   * attributes that returned true when passed to IsAttributeMapped.  The
+   * caller will not try to set the attr in any other way if this method
+   * returns true (the value of aRetval does not matter for that purpose).
+   *
+   * @param aDocument the current document of this node (an optimization)
+   * @param aName the name of the attribute
+   * @param aValue the nsAttrValue to set
+   * @param [out] aRetval the nsresult status of the operation, if any.
+   * @return true if the setting was attempted, false otherwise.
+   */
+  virtual bool SetMappedAttribute(nsIDocument* aDocument,
+                                    nsIAtom* aName,
+                                    nsAttrValue& aValue,
+                                    nsresult* aRetval);
+
+  /**
+   * Hook that is called by Element::SetAttr to allow subclasses to
+   * deal with attribute sets.  This will only be called after we verify that
+   * we're actually doing an attr set and will be called before
+   * AttributeWillChange and before ParseAttribute and hence before we've set
+   * the new value.
+   *
+   * @param aNamespaceID the namespace of the attr being set
+   * @param aName the localname of the attribute being set
+   * @param aValue the value it's being set to represented as either a string or
+   *        a parsed nsAttrValue. Alternatively, if the attr is being removed it
+   *        will be null. BeforeSetAttr is allowed to modify aValue by parsing
+   *        the string to an nsAttrValue (to avoid having to reparse it in
+   *        ParseAttribute).
+   * @param aNotify Whether we plan to notify document observers.
+   */
+  // Note that this is inlined so that when subclasses call it it gets
+  // inlined.  Those calls don't go through a vtable.
+  virtual nsresult BeforeSetAttr(int32_t aNamespaceID, nsIAtom* aName,
+                                 nsAttrValueOrString* aValue,
+                                 bool aNotify);
+
+  /**
+   * Hook that is called by Element::SetAttr to allow subclasses to
+   * deal with attribute sets.  This will only be called after we have called
+   * SetAndTakeAttr and AttributeChanged (that is, after we have actually set
+   * the attr).  It will always be called under a scriptblocker.
+   *
+   * @param aNamespaceID the namespace of the attr being set
+   * @param aName the localname of the attribute being set
+   * @param aValue the value it's being set to.  If null, the attr is being
+   *        removed.
+   * @param aNotify Whether we plan to notify document observers.
+   */
+  // Note that this is inlined so that when subclasses call it it gets
+  // inlined.  Those calls don't go through a vtable.
+  virtual nsresult AfterSetAttr(int32_t aNamespaceID, nsIAtom* aName,
+                                const nsAttrValue* aValue, bool aNotify)
+  {
+    return NS_OK;
+  }
+
+  /**
+   * Hook to allow subclasses to produce a different EventListenerManager if
+   * needed for attachment of attribute-defined handlers
+   */
+  virtual EventListenerManager*
+    GetEventListenerManagerForAttr(nsIAtom* aAttrName, bool* aDefer);
+
+  /**
+   * Internal hook for converting an attribute name-string to nsAttrName in
+   * case there is such existing attribute. aNameToUse can be passed to get
+   * name which was used for looking for the attribute (lowercase in HTML).
+   */
+  const nsAttrName*
+  InternalGetAttrNameFromQName(const nsAString& aStr,
+                               nsAutoString* aNameToUse = nullptr) const;
+
+  nsIFrame* GetStyledFrame();
+
+  virtual Element* GetNameSpaceElement() override
+  {
+    return this;
+  }
+
+  Attr* GetAttributeNodeNSInternal(const nsAString& aNamespaceURI,
+                                   const nsAString& aLocalName);
+
+  inline void RegisterActivityObserver();
+  inline void UnregisterActivityObserver();
+
+  /**
+   * Add/remove this element to the documents id cache
+   */
+  void AddToIdTable(nsIAtom* aId);
+  void RemoveFromIdTable();
+
+  /**
+   * Functions to carry out event default actions for links of all types
+   * (HTML links, XLinks, SVG "XLinks", etc.)
+   */
+
+  /**
+   * Check that we meet the conditions to handle a link event
+   * and that we are actually on a link.
+   *
+   * @param aVisitor event visitor
+   * @param aURI the uri of the link, set only if the return value is true [OUT]
+   * @return true if we can handle the link event, false otherwise
+   */
+  bool CheckHandleEventForLinksPrecondition(EventChainVisitor& aVisitor,
+                                            nsIURI** aURI) const;
+
+  /**
+   * Handle status bar updates before they can be cancelled.
+   */
+  nsresult PreHandleEventForLinks(EventChainPreVisitor& aVisitor);
+
+  /**
+   * Handle default actions for link event if the event isn't consumed yet.
+   */
+  nsresult PostHandleEventForLinks(EventChainPostVisitor& aVisitor);
+
+  /**
+   * Get the target of this link element. Consumers should established that
+   * this element is a link (probably using IsLink) before calling this
+   * function (or else why call it?)
+   *
+   * Note: for HTML this gets the value of the 'target' attribute; for XLink
+   * this gets the value of the xlink:_moz_target attribute, or failing that,
+   * the value of xlink:show, converted to a suitably equivalent named target
+   * (e.g. _blank).
+   */
+  virtual void GetLinkTarget(nsAString& aTarget);
+
+  nsDOMTokenList* GetTokenList(nsIAtom* aAtom,
+                               const DOMTokenListSupportedTokenArray aSupportedTokens = nullptr);
+
+  nsTArray<nsDOMSlots::IntersectionObserverRegistration>* RegisteredIntersectionObservers();
+
+private:
+  /**
+   * Get this element's client area rect in app units.
+   * @return the frame's client area
+   */
+  nsRect GetClientAreaRect();
+
+  nsIScrollableFrame* GetScrollFrame(nsIFrame **aStyledFrame = nullptr,
+                                     bool aFlushLayout = true);
+
+  // Data members
+  EventStates mState;
+};
+
+class RemoveFromBindingManagerRunnable : public mozilla::Runnable
+{
+public:
+  RemoveFromBindingManagerRunnable(nsBindingManager* aManager,
+                                   nsIContent* aContent,
+                                   nsIDocument* aDoc);
+
+  NS_IMETHOD Run() override;
+private:
+  virtual ~RemoveFromBindingManagerRunnable();
+  RefPtr<nsBindingManager> mManager;
+  RefPtr<nsIContent> mContent;
+  nsCOMPtr<nsIDocument> mDoc;
+};
+
+class DestinationInsertionPointList : public nsINodeList
+{
+public:
+  explicit DestinationInsertionPointList(Element* aElement);
+
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DestinationInsertionPointList)
+
+  // nsIDOMNodeList
+  NS_DECL_NSIDOMNODELIST
+
+  // nsINodeList
+  virtual nsIContent* Item(uint32_t aIndex) override;
+  virtual int32_t IndexOf(nsIContent* aContent) override;
+  virtual nsINode* GetParentObject() override { return mParent; }
+  virtual uint32_t Length() const;
+  virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+protected:
+  virtual ~DestinationInsertionPointList();
+
+  RefPtr<Element> mParent;
+  nsCOMArray<nsIContent> mDestinationPoints;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(Element, NS_ELEMENT_IID)
+
+inline bool
+Element::HasAttr(int32_t aNameSpaceID, nsIAtom* aName) const
+{
+  NS_ASSERTION(nullptr != aName, "must have attribute name");
+  NS_ASSERTION(aNameSpaceID != kNameSpaceID_Unknown,
+               "must have a real namespace ID!");
+
+  return mAttrsAndChildren.IndexOfAttr(aName, aNameSpaceID) >= 0;
+}
+
+inline bool
+Element::AttrValueIs(int32_t aNameSpaceID,
+                     nsIAtom* aName,
+                     const nsAString& aValue,
+                     nsCaseTreatment aCaseSensitive) const
+{
+  NS_ASSERTION(aName, "Must have attr name");
+  NS_ASSERTION(aNameSpaceID != kNameSpaceID_Unknown, "Must have namespace");
+
+  const nsAttrValue* val = mAttrsAndChildren.GetAttr(aName, aNameSpaceID);
+  return val && val->Equals(aValue, aCaseSensitive);
+}
+
+inline bool
+Element::AttrValueIs(int32_t aNameSpaceID,
+                     nsIAtom* aName,
+                     nsIAtom* aValue,
+                     nsCaseTreatment aCaseSensitive) const
+{
+  NS_ASSERTION(aName, "Must have attr name");
+  NS_ASSERTION(aNameSpaceID != kNameSpaceID_Unknown, "Must have namespace");
+  NS_ASSERTION(aValue, "Null value atom");
+
+  const nsAttrValue* val = mAttrsAndChildren.GetAttr(aName, aNameSpaceID);
+  return val && val->Equals(aValue, aCaseSensitive);
+}
+
+} // namespace dom
+} // namespace mozilla
+
+inline mozilla::dom::Element* nsINode::AsElement()
+{
+  MOZ_ASSERT(IsElement());
+  return static_cast<mozilla::dom::Element*>(this);
+}
+
+inline const mozilla::dom::Element* nsINode::AsElement() const
+{
+  MOZ_ASSERT(IsElement());
+  return static_cast<const mozilla::dom::Element*>(this);
+}
+
+inline void nsINode::UnsetRestyleFlagsIfGecko()
+{
+  if (IsElement() && !IsStyledByServo()) {
+    UnsetFlags(ELEMENT_ALL_RESTYLE_FLAGS);
+  }
+}
+
+/**
+ * Macros to implement Clone(). _elementName is the class for which to implement
+ * Clone.
+ */
+#define NS_IMPL_ELEMENT_CLONE(_elementName)                                 \
+nsresult                                                                    \
+_elementName::Clone(mozilla::dom::NodeInfo *aNodeInfo, nsINode **aResult) const \
+{                                                                           \
+  *aResult = nullptr;                                                       \
+  already_AddRefed<mozilla::dom::NodeInfo> ni =                             \
+    RefPtr<mozilla::dom::NodeInfo>(aNodeInfo).forget();                   \
+  _elementName *it = new _elementName(ni);                                  \
+  if (!it) {                                                                \
+    return NS_ERROR_OUT_OF_MEMORY;                                          \
+  }                                                                         \
+                                                                            \
+  nsCOMPtr<nsINode> kungFuDeathGrip = it;                                   \
+  nsresult rv = const_cast<_elementName*>(this)->CopyInnerTo(it);           \
+  if (NS_SUCCEEDED(rv)) {                                                   \
+    kungFuDeathGrip.swap(*aResult);                                         \
+  }                                                                         \
+                                                                            \
+  return rv;                                                                \
+}
+
+#define NS_IMPL_ELEMENT_CLONE_WITH_INIT(_elementName)                       \
+nsresult                                                                    \
+_elementName::Clone(mozilla::dom::NodeInfo *aNodeInfo, nsINode **aResult) const \
+{                                                                           \
+  *aResult = nullptr;                                                       \
+  already_AddRefed<mozilla::dom::NodeInfo> ni =                             \
+    RefPtr<mozilla::dom::NodeInfo>(aNodeInfo).forget();                   \
+  _elementName *it = new _elementName(ni);                                  \
+  if (!it) {                                                                \
+    return NS_ERROR_OUT_OF_MEMORY;                                          \
+  }                                                                         \
+                                                                            \
+  nsCOMPtr<nsINode> kungFuDeathGrip = it;                                   \
+  nsresult rv = it->Init();                                                 \
+  nsresult rv2 = const_cast<_elementName*>(this)->CopyInnerTo(it);          \
+  if (NS_FAILED(rv2)) {                                                     \
+    rv = rv2;                                                               \
+  }                                                                         \
+  if (NS_SUCCEEDED(rv)) {                                                   \
+    kungFuDeathGrip.swap(*aResult);                                         \
+  }                                                                         \
+                                                                            \
+  return rv;                                                                \
+}
+
+/**
+ * A macro to implement the getter and setter for a given string
+ * valued content property. The method uses the generic GetAttr and
+ * SetAttr methods.  We use the 5-argument form of SetAttr, because
+ * some consumers only implement that one, hiding superclass
+ * 4-argument forms.
+ */
+#define NS_IMPL_STRING_ATTR(_class, _method, _atom)                     \
+  NS_IMETHODIMP                                                         \
+  _class::Get##_method(nsAString& aValue)                               \
+  {                                                                     \
+    GetAttr(kNameSpaceID_None, nsGkAtoms::_atom, aValue);               \
+    return NS_OK;                                                       \
+  }                                                                     \
+  NS_IMETHODIMP                                                         \
+  _class::Set##_method(const nsAString& aValue)                         \
+  {                                                                     \
+    return SetAttr(kNameSpaceID_None, nsGkAtoms::_atom, nullptr, aValue, true); \
+  }
+
+/**
+ * A macro to implement the getter and setter for a given boolean
+ * valued content property. The method uses the GetBoolAttr and
+ * SetBoolAttr methods.
+ */
+#define NS_IMPL_BOOL_ATTR(_class, _method, _atom)                     \
+  NS_IMETHODIMP                                                       \
+  _class::Get##_method(bool* aValue)                                  \
+  {                                                                   \
+    *aValue = GetBoolAttr(nsGkAtoms::_atom);                          \
+    return NS_OK;                                                     \
+  }                                                                   \
+  NS_IMETHODIMP                                                       \
+  _class::Set##_method(bool aValue)                                   \
+  {                                                                   \
+    return SetBoolAttr(nsGkAtoms::_atom, aValue);                     \
+  }
+
+#define NS_FORWARD_NSIDOMELEMENT_TO_GENERIC                                   \
+typedef mozilla::dom::Element Element;                                        \
+NS_IMETHOD GetTagName(nsAString& aTagName) final override                     \
+{                                                                             \
+  Element::GetTagName(aTagName);                                              \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetId(nsAString& aId) final override                               \
+{                                                                             \
+  Element::GetId(aId);                                                        \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD SetId(const nsAString& aId) final override                         \
+{                                                                             \
+  Element::SetId(aId);                                                        \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetClassName(nsAString& aClassName) final override                 \
+{                                                                             \
+  Element::GetClassName(aClassName);                                          \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD SetClassName(const nsAString& aClassName) final override           \
+{                                                                             \
+  Element::SetClassName(aClassName);                                          \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetClassList(nsISupports** aClassList) final override              \
+{                                                                             \
+  Element::GetClassList(aClassList);                                          \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetAttributes(nsIDOMMozNamedAttrMap** aAttributes) final override  \
+{                                                                             \
+  NS_ADDREF(*aAttributes = Attributes());                                     \
+  return NS_OK;                                                               \
+}                                                                             \
+using Element::GetAttribute;                                                  \
+NS_IMETHOD GetAttribute(const nsAString& name, nsAString& _retval) final      \
+  override                                                                    \
+{                                                                             \
+  nsString attr;                                                              \
+  GetAttribute(name, attr);                                                   \
+  _retval = attr;                                                             \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetAttributeNS(const nsAString& namespaceURI,                      \
+                          const nsAString& localName,                         \
+                          nsAString& _retval) final override                  \
+{                                                                             \
+  Element::GetAttributeNS(namespaceURI, localName, _retval);                  \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD SetAttribute(const nsAString& name,                                \
+                        const nsAString& value) override                      \
+{                                                                             \
+  mozilla::ErrorResult rv;                                                    \
+  Element::SetAttribute(name, value, rv);                                     \
+  return rv.StealNSResult();                                                  \
+}                                                                             \
+NS_IMETHOD SetAttributeNS(const nsAString& namespaceURI,                      \
+                          const nsAString& qualifiedName,                     \
+                          const nsAString& value) final override              \
+{                                                                             \
+  mozilla::ErrorResult rv;                                                    \
+  Element::SetAttributeNS(namespaceURI, qualifiedName, value, rv);            \
+  return rv.StealNSResult();                                                      \
+}                                                                             \
+using Element::RemoveAttribute;                                               \
+NS_IMETHOD RemoveAttribute(const nsAString& name) final override              \
+{                                                                             \
+  mozilla::ErrorResult rv;                                                    \
+  RemoveAttribute(name, rv);                                                  \
+  return rv.StealNSResult();                                                      \
+}                                                                             \
+NS_IMETHOD RemoveAttributeNS(const nsAString& namespaceURI,                   \
+                             const nsAString& localName) final override       \
+{                                                                             \
+  mozilla::ErrorResult rv;                                                    \
+  Element::RemoveAttributeNS(namespaceURI, localName, rv);                    \
+  return rv.StealNSResult();                                                      \
+}                                                                             \
+using Element::HasAttribute;                                                  \
+NS_IMETHOD HasAttribute(const nsAString& name,                                \
+                           bool* _retval) final override                      \
+{                                                                             \
+  *_retval = HasAttribute(name);                                              \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD HasAttributeNS(const nsAString& namespaceURI,                      \
+                          const nsAString& localName,                         \
+                          bool* _retval) final override                       \
+{                                                                             \
+  *_retval = Element::HasAttributeNS(namespaceURI, localName);                \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD HasAttributes(bool* _retval) final override                        \
+{                                                                             \
+  *_retval = Element::HasAttributes();                                        \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetAttributeNode(const nsAString& name,                            \
+                            nsIDOMAttr** _retval) final override              \
+{                                                                             \
+  NS_IF_ADDREF(*_retval = Element::GetAttributeNode(name));                   \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD SetAttributeNode(nsIDOMAttr* newAttr,                              \
+                            nsIDOMAttr** _retval) final override              \
+{                                                                             \
+  if (!newAttr) {                                                             \
+    return NS_ERROR_INVALID_POINTER;                                          \
+  }                                                                           \
+  mozilla::ErrorResult rv;                                                    \
+  mozilla::dom::Attr* attr = static_cast<mozilla::dom::Attr*>(newAttr);       \
+  *_retval = Element::SetAttributeNode(*attr, rv).take();                     \
+  return rv.StealNSResult();                                                      \
+}                                                                             \
+NS_IMETHOD RemoveAttributeNode(nsIDOMAttr* oldAttr,                           \
+                               nsIDOMAttr** _retval) final override           \
+{                                                                             \
+  if (!oldAttr) {                                                             \
+    return NS_ERROR_INVALID_POINTER;                                          \
+  }                                                                           \
+  mozilla::ErrorResult rv;                                                    \
+  mozilla::dom::Attr* attr = static_cast<mozilla::dom::Attr*>(oldAttr);       \
+  *_retval = Element::RemoveAttributeNode(*attr, rv).take();                  \
+  return rv.StealNSResult();                                                      \
+}                                                                             \
+NS_IMETHOD GetAttributeNodeNS(const nsAString& namespaceURI,                  \
+                              const nsAString& localName,                     \
+                              nsIDOMAttr** _retval) final override            \
+{                                                                             \
+  NS_IF_ADDREF(*_retval = Element::GetAttributeNodeNS(namespaceURI,           \
+                                                      localName));            \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD SetAttributeNodeNS(nsIDOMAttr* newAttr,                            \
+                              nsIDOMAttr** _retval) final override            \
+{                                                                             \
+  mozilla::ErrorResult rv;                                                    \
+  mozilla::dom::Attr* attr = static_cast<mozilla::dom::Attr*>(newAttr);       \
+  *_retval = Element::SetAttributeNodeNS(*attr, rv).take();                   \
+  return rv.StealNSResult();                                                      \
+}                                                                             \
+NS_IMETHOD GetElementsByTagName(const nsAString& name,                        \
+                                nsIDOMHTMLCollection** _retval) final         \
+                                                                override      \
+{                                                                             \
+  Element::GetElementsByTagName(name, _retval);                               \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetElementsByTagNameNS(const nsAString& namespaceURI,              \
+                                  const nsAString& localName,                 \
+                                  nsIDOMHTMLCollection** _retval) final       \
+                                                                  override    \
+{                                                                             \
+  return Element::GetElementsByTagNameNS(namespaceURI, localName,             \
+                                         _retval);                            \
+}                                                                             \
+NS_IMETHOD GetElementsByClassName(const nsAString& classes,                   \
+                                  nsIDOMHTMLCollection** _retval) final       \
+                                                                  override    \
+{                                                                             \
+  return Element::GetElementsByClassName(classes, _retval);                   \
+}                                                                             \
+NS_IMETHOD GetChildElements(nsIDOMNodeList** aChildElements) final override   \
+{                                                                             \
+  nsIHTMLCollection* list = FragmentOrElement::Children();                    \
+  return CallQueryInterface(list, aChildElements);                            \
+}                                                                             \
+NS_IMETHOD GetFirstElementChild(nsIDOMElement** aFirstElementChild) final     \
+  override                                                                    \
+{                                                                             \
+  Element* element = Element::GetFirstElementChild();                         \
+  if (!element) {                                                             \
+    *aFirstElementChild = nullptr;                                            \
+    return NS_OK;                                                             \
+  }                                                                           \
+  return CallQueryInterface(element, aFirstElementChild);                     \
+}                                                                             \
+NS_IMETHOD GetLastElementChild(nsIDOMElement** aLastElementChild) final       \
+  override                                                                    \
+{                                                                             \
+  Element* element = Element::GetLastElementChild();                          \
+  if (!element) {                                                             \
+    *aLastElementChild = nullptr;                                             \
+    return NS_OK;                                                             \
+  }                                                                           \
+  return CallQueryInterface(element, aLastElementChild);                      \
+}                                                                             \
+NS_IMETHOD GetPreviousElementSibling(nsIDOMElement** aPreviousElementSibling) \
+  final override                                                              \
+{                                                                             \
+  Element* element = Element::GetPreviousElementSibling();                    \
+  if (!element) {                                                             \
+    *aPreviousElementSibling = nullptr;                                       \
+    return NS_OK;                                                             \
+  }                                                                           \
+  return CallQueryInterface(element, aPreviousElementSibling);                \
+}                                                                             \
+NS_IMETHOD GetNextElementSibling(nsIDOMElement** aNextElementSibling)         \
+  final override                                                              \
+{                                                                             \
+  Element* element = Element::GetNextElementSibling();                        \
+  if (!element) {                                                             \
+    *aNextElementSibling = nullptr;                                           \
+    return NS_OK;                                                             \
+  }                                                                           \
+  return CallQueryInterface(element, aNextElementSibling);                    \
+}                                                                             \
+NS_IMETHOD GetChildElementCount(uint32_t* aChildElementCount) final override  \
+{                                                                             \
+  *aChildElementCount = Element::ChildElementCount();                         \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD MozRemove() final override                                         \
+{                                                                             \
+  nsINode::Remove();                                                          \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetClientRects(nsIDOMClientRectList** _retval) final override      \
+{                                                                             \
+  *_retval = Element::GetClientRects().take();                                \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetBoundingClientRect(nsIDOMClientRect** _retval) final override   \
+{                                                                             \
+  *_retval = Element::GetBoundingClientRect().take();                         \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetScrollTop(int32_t* aScrollTop) final override                   \
+{                                                                             \
+  *aScrollTop = Element::ScrollTop();                                         \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD SetScrollTop(int32_t aScrollTop) final override                    \
+{                                                                             \
+  Element::SetScrollTop(aScrollTop);                                          \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetScrollLeft(int32_t* aScrollLeft) final override                 \
+{                                                                             \
+  *aScrollLeft = Element::ScrollLeft();                                       \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD SetScrollLeft(int32_t aScrollLeft) final override                  \
+{                                                                             \
+  Element::SetScrollLeft(aScrollLeft);                                        \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetScrollWidth(int32_t* aScrollWidth) final override               \
+{                                                                             \
+  *aScrollWidth = Element::ScrollWidth();                                     \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetScrollHeight(int32_t* aScrollHeight) final override             \
+{                                                                             \
+  *aScrollHeight = Element::ScrollHeight();                                   \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetClientTop(int32_t* aClientTop) final override                   \
+{                                                                             \
+  *aClientTop = Element::ClientTop();                                         \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetClientLeft(int32_t* aClientLeft) final override                 \
+{                                                                             \
+  *aClientLeft = Element::ClientLeft();                                       \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetClientWidth(int32_t* aClientWidth) final override               \
+{                                                                             \
+  *aClientWidth = Element::ClientWidth();                                     \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetClientHeight(int32_t* aClientHeight) final override             \
+{                                                                             \
+  *aClientHeight = Element::ClientHeight();                                   \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetScrollLeftMax(int32_t* aScrollLeftMax) final override           \
+{                                                                             \
+  *aScrollLeftMax = Element::ScrollLeftMax();                                 \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD GetScrollTopMax(int32_t* aScrollTopMax) final override             \
+{                                                                             \
+  *aScrollTopMax = Element::ScrollTopMax();                                   \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD MozMatchesSelector(const nsAString& selector,                      \
+                              bool* _retval) final override                   \
+{                                                                             \
+  mozilla::ErrorResult rv;                                                    \
+  *_retval = Element::Matches(selector, rv);                                  \
+  return rv.StealNSResult();                                                  \
+}                                                                             \
+NS_IMETHOD SetCapture(bool retargetToElement) final override                  \
+{                                                                             \
+  Element::SetCapture(retargetToElement);                                     \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD ReleaseCapture(void) final override                                \
+{                                                                             \
+  Element::ReleaseCapture();                                                  \
+  return NS_OK;                                                               \
+}                                                                             \
+NS_IMETHOD MozRequestFullScreen(void) final override                          \
+{                                                                             \
+  mozilla::ErrorResult rv;                                                    \
+  Element::RequestFullscreen(rv);                                    \
+  return rv.StealNSResult();                                                  \
+}                                                                             \
+NS_IMETHOD MozRequestPointerLock(void) final override                         \
+{                                                                             \
+  Element::RequestPointerLock();                                              \
+  return NS_OK;                                                               \
+}                                                                             \
+using nsINode::QuerySelector;                                                 \
+NS_IMETHOD QuerySelector(const nsAString& aSelector,                          \
+                         nsIDOMElement **aReturn) final override              \
+{                                                                             \
+  return nsINode::QuerySelector(aSelector, aReturn);                          \
+}                                                                             \
+using nsINode::QuerySelectorAll;                                              \
+NS_IMETHOD QuerySelectorAll(const nsAString& aSelector,                       \
+                            nsIDOMNodeList **aReturn) final override          \
+{                                                                             \
+  return nsINode::QuerySelectorAll(aSelector, aReturn);                       \
+}
+
+#endif // mozilla_dom_Element_h__