LibWeb: Add fast_is<TextPaintable>()

Userland/Libraries/LibWeb/Painting/Paintable.h

@@ -200,6 +200,7 @@ public:
     [[nodiscard]] virtual bool is_paintable_with_lines() const { return false; }
     [[nodiscard]] virtual bool is_inline_paintable() const { return false; }
     [[nodiscard]] virtual bool is_svg_paintable() const { return false; }
+    [[nodiscard]] virtual bool is_text_paintable() const { return false; }
 
     DOM::Document const& document() const { return layout_node().document(); }
     DOM::Document& document() { return layout_node().document(); }
@@ -256,4 +257,7 @@ inline bool Paintable::fast_is<PaintableBox>() const { return is_paintable_box()
 template<>
 inline bool Paintable::fast_is<PaintableWithLines>() const { return is_paintable_with_lines(); }
 
+template<>
+inline bool Paintable::fast_is<TextPaintable>() const { return is_text_paintable(); }
+
 }

Userland/Libraries/LibWeb/Painting/TextPaintable.h

@@ -28,6 +28,8 @@ public:
     CSSPixels text_decoration_thickness() const { return m_text_decoration_thickness; }
 
 private:
+    virtual bool is_text_paintable() const override { return true; }
+
     explicit TextPaintable(Layout::TextNode const&);
 
     CSSPixels m_text_decoration_thickness { 0 };