LibWeb: Don't store separate computed value for font_size

The StyleValue stored in m_property_values is already in it's computed
form and it's trivial to pull the underlying value out so there is no
need to store this separately.

Also removes unnecessary handling of percentage values in
`absolutize_values` - this is already handled within `compute_font`.

Libraries/LibWeb/CSS/ComputedProperties.cpp

@@ -1977,4 +1977,9 @@ WillChange ComputedProperties::will_change() const
     return WillChange::make_auto();
 }
 
+CSSPixels ComputedProperties::font_size() const
+{
+    return property(PropertyID::FontSize).as_length().length().absolute_length_to_px();
+}
+
 }

Libraries/LibWeb/CSS/ComputedProperties.h

@@ -227,8 +227,7 @@ public:
 
     [[nodiscard]] CSSPixels line_height() const { return *m_line_height; }
     void set_line_height(Badge<StyleComputer> const&, CSSPixels line_height) { m_line_height = line_height; }
-    [[nodiscard]] CSSPixels font_size() const { return *m_font_size; }
+    [[nodiscard]] CSSPixels font_size() const;
-    void set_font_size(Badge<StyleComputer> const&, CSSPixels font_size) { m_font_size = font_size; }
 
     bool operator==(ComputedProperties const&) const;
 
@@ -283,7 +282,6 @@ private:
     RefPtr<Gfx::Font const> m_first_available_computed_font;
 
     Optional<CSSPixels> m_line_height;
-    Optional<CSSPixels> m_font_size;
 
     PseudoClassBitmap m_attempted_pseudo_class_matches;
 };

Libraries/LibWeb/CSS/StyleComputer.cpp

@@ -1098,7 +1098,7 @@ void StyleComputer::collect_animation_into(DOM::Element& element, Optional<CSS::
         };
 
         compute_font(computed_properties, &element, pseudo_element);
-        absolutize_values(computed_properties, element);
+        absolutize_values(computed_properties);
         Length::FontMetrics font_metrics {
             computed_properties.font_size(),
             computed_properties.first_available_computed_font().pixel_metrics()
@@ -2136,25 +2136,13 @@ Gfx::Font const& StyleComputer::initial_font() const
     return font;
 }
 
-void StyleComputer::absolutize_values(ComputedProperties& style, GC::Ptr<DOM::Element const> element) const
+void StyleComputer::absolutize_values(ComputedProperties& style) const
 {
     Length::FontMetrics font_metrics {
-        root_element_font_metrics_for_element(element).font_size,
+        style.font_size(),
         style.first_available_computed_font().pixel_metrics()
     };
 
-    // "A percentage value specifies an absolute font size relative to the parent element’s computed font-size. Negative percentages are invalid."
-    auto& font_size_value_slot = style.m_property_values[to_underlying(CSS::PropertyID::FontSize)];
-    if (font_size_value_slot && font_size_value_slot->is_percentage()) {
-        auto parent_font_size = get_inherit_value(CSS::PropertyID::FontSize, element)->as_length().length().to_px(viewport_rect(), font_metrics, m_root_element_font_metrics);
-        font_size_value_slot = LengthStyleValue::create(
-            Length::make_px(CSSPixels::nearest_value_for(parent_font_size * font_size_value_slot->as_percentage().percentage().as_fraction())));
-    }
-
-    auto font_size = font_size_value_slot->as_length().length().to_px(viewport_rect(), font_metrics, m_root_element_font_metrics);
-    font_metrics.font_size = font_size;
-    style.set_font_size({}, font_size);
-
     // NOTE: Percentage line-height values are relative to the font-size of the element.
     //       We have to resolve them right away, so that the *computed* line-height is ready for inheritance.
     //       We can't simply absolutize *all* percentage values against the font size,
@@ -2162,7 +2150,7 @@ void StyleComputer::absolutize_values(ComputedProperties& style, GC::Ptr<DOM::El
     auto& line_height_value_slot = style.m_property_values[to_underlying(CSS::PropertyID::LineHeight)];
     if (line_height_value_slot && line_height_value_slot->is_percentage()) {
         line_height_value_slot = LengthStyleValue::create(
-            Length::make_px(CSSPixels::nearest_value_for(font_size * static_cast<double>(line_height_value_slot->as_percentage().percentage().as_fraction()))));
+            Length::make_px(CSSPixels::nearest_value_for(style.font_size() * static_cast<double>(line_height_value_slot->as_percentage().percentage().as_fraction()))));
     }
 
     auto line_height = style.compute_line_height(viewport_rect(), font_metrics, m_root_element_font_metrics);
@@ -2396,7 +2384,7 @@ GC::Ref<ComputedProperties> StyleComputer::create_document_style() const
 
     compute_math_depth(style, {});
     compute_font(style, nullptr, {});
-    absolutize_values(style, nullptr);
+    absolutize_values(style);
     style->set_property(CSS::PropertyID::Width, CSS::LengthStyleValue::create(CSS::Length::make_px(viewport_rect().width())));
     style->set_property(CSS::PropertyID::Height, CSS::LengthStyleValue::create(CSS::Length::make_px(viewport_rect().height())));
     style->set_property(CSS::PropertyID::Display, CSS::DisplayStyleValue::create(CSS::Display::from_short(CSS::Display::Short::Block)));
@@ -2708,7 +2696,7 @@ GC::Ref<ComputedProperties> StyleComputer::compute_properties(DOM::Element& elem
     compute_font(computed_style, &element, pseudo_element);
 
     // 4. Absolutize values, turning font/viewport relative lengths into absolute lengths
-    absolutize_values(computed_style, element);
+    absolutize_values(computed_style);
 
     // 5. Run automatic box type transformations
     transform_box_type_if_needed(computed_style, element, pseudo_element);

Libraries/LibWeb/CSS/StyleComputer.h

@@ -193,7 +193,7 @@ public:
 
     [[nodiscard]] GC::Ref<ComputedProperties> compute_properties(DOM::Element&, Optional<PseudoElement>, CascadedProperties&) const;
 
-    void absolutize_values(ComputedProperties&, GC::Ptr<DOM::Element const>) const;
+    void absolutize_values(ComputedProperties&) const;
     void compute_font(ComputedProperties&, DOM::Element const*, Optional<CSS::PseudoElement>) const;
 
     [[nodiscard]] inline bool should_reject_with_ancestor_filter(Selector const&) const;

Libraries/LibWeb/DOM/Element.cpp

@@ -839,7 +839,7 @@ CSS::RequiredInvalidationAfterStyleChange Element::recompute_inherited_style()
         return invalidation;
 
     document().style_computer().compute_font(*computed_properties, this, {});
-    document().style_computer().absolutize_values(*computed_properties, this);
+    document().style_computer().absolutize_values(*computed_properties);
 
     for (auto [property_id, old_value] : old_values_with_relative_units) {
         auto new_value = computed_properties->maybe_null_property(static_cast<CSS::PropertyID>(property_id));