LibWeb: Remove more hand-rolled type information :^)

Hoo boy, we've really accumulated a lot of this stuff.

Libraries/LibWeb/DOM/Event.cpp

@@ -39,7 +39,7 @@ void Event::append_to_path(EventTarget& invocation_target, RefPtr<EventTarget> s
 
     if (is<Node>(invocation_target)) {
         auto& invocation_target_node = downcast<Node>(invocation_target);
-        if (invocation_target_node.root()->is_shadow_root())
+        if (is<ShadowRoot>(invocation_target_node.root()))
             invocation_target_in_shadow_tree = true;
         if (is<ShadowRoot>(invocation_target_node)) {
             auto& invocation_target_shadow_root = downcast<ShadowRoot>(invocation_target_node);

Libraries/LibWeb/DOM/Event.h

@@ -149,9 +149,6 @@ public:
         m_stop_immediate_propagation = true;
     }
 
-    virtual bool is_ui_event() const { return false; }
-    virtual bool is_mouse_event() const { return false; }
-
 protected:
     explicit Event(const FlyString& type)
         : m_type(type)

Libraries/LibWeb/DOM/EventDispatcher.cpp

@@ -57,7 +57,7 @@ static EventTarget* retarget(EventTarget* left, [[maybe_unused]] EventTarget* ri
 
         auto* left_node = downcast<Node>(left);
         auto* left_root = left_node->root();
-        if (!left_root->is_shadow_root())
+        if (!is<ShadowRoot>(left_root))
             return left;
 
         // FIXME: If right is a node and left’s root is a shadow-including inclusive ancestor of right, return left.

Libraries/LibWeb/DOM/EventTarget.h

@@ -63,9 +63,6 @@ public:
 
     const Vector<EventListenerRegistration>& listeners() const { return m_listeners; }
 
-    virtual bool is_node() const { return false; }
-    virtual bool is_window() const { return false; }
-
     Function<void(const Event&)> activation_behaviour;
 
     // NOTE: These only exist for checkbox and radio input elements.

Libraries/LibWeb/DOM/Node.h

@@ -77,10 +77,6 @@ public:
     bool is_document_fragment() const { return type() == NodeType::DOCUMENT_FRAGMENT_NODE; }
     bool is_parent_node() const { return is_element() || is_document() || is_document_fragment(); }
     bool is_slottable() const { return is_element() || is_text(); }
-    virtual bool is_svg_element() const { return false; }
-    virtual bool is_shadow_root() const { return false; }
-
-    virtual bool is_node() const final { return true; }
 
     virtual bool is_editable() const;
 
@@ -103,9 +99,6 @@ public:
 
     String child_text_content() const;
 
-    virtual bool is_html_element() const { return false; }
-    virtual bool is_unknown_html_element() const { return false; }
-
     Node* root();
     const Node* root() const
     {

Libraries/LibWeb/DOM/ShadowRoot.h

@@ -42,9 +42,6 @@ public:
     bool available_to_element_internals() const { return m_available_to_element_internals; }
     void set_available_to_element_internals(bool available_to_element_internals) { m_available_to_element_internals = available_to_element_internals; }
 
-    // ^Node
-    virtual bool is_shadow_root() const override { return true; }
-
     // ^EventTarget
     virtual EventTarget* get_parent(const Event&) override;
 

Libraries/LibWeb/DOM/Window.h

@@ -79,8 +79,6 @@ public:
 
     HighResolutionTime::Performance& performance() { return *m_performance; }
 
-    virtual bool is_window() const override { return true; }
-
     const Event* current_event() const { return m_current_event; }
     void set_current_event(Event* event) { m_current_event = event; }