LibWeb: Set inertness of HTMLElement when inert attribute is changed

Author: https://github.com/tcl3
Commit: a9ffc6359a
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3475
Reviewed-by: https://github.com/AtkinsSJ ✅

Libraries/LibWeb/HTML/HTMLElement.h

@@ -149,6 +149,8 @@ public:
     static void hide_all_popovers_until(Variant<GC::Ptr<HTMLElement>, GC::Ptr<DOM::Document>> endpoint, FocusPreviousElement focus_previous_element, FireEvents fire_events);
     static GC::Ptr<HTMLElement> topmost_popover_ancestor(GC::Ptr<DOM::Node> new_popover_or_top_layer_element, Vector<GC::Ref<HTMLElement>> const& popover_list, GC::Ptr<HTMLElement> invoker, IsPopover is_popover);
 
+    bool is_inert() const { return m_inert; }
+
 protected:
     HTMLElement(DOM::Document&, DOM::QualifiedName);
 
@@ -169,6 +171,9 @@ protected:
     // https://html.spec.whatwg.org/multipage/urls-and-fetching.html#implicitly-potentially-render-blocking
     virtual bool is_implicitly_potentially_render_blocking() const { return false; }
 
+    void set_inert(bool inert) { m_inert = inert; }
+    void set_subtree_inertness(bool is_inert);
+
 private:
     virtual bool is_html_element() const final { return true; }
 
@@ -200,6 +205,8 @@ private:
     // https://html.spec.whatwg.org/multipage/interaction.html#click-in-progress-flag
     bool m_click_in_progress { false };
 
+    bool m_inert { false };
+
     // Popover API
 
     // https://html.spec.whatwg.org/multipage/popover.html#popover-visibility-state