LibWeb: Parse scroll() for the animation-timeline CSS property

Author: https://github.com/Calme1709
Commit: https://github.com/LadybirdBrowser/ladybird/commit/7d70714eac3
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/6912
Reviewed-by: https://github.com/AtkinsSJ ✅

Libraries/LibWeb/CSS/StyleValues/ScrollFunctionStyleValue.h

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2025, Callum Law <callumlaw1709@outlook.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/CSS/Enums.h>
+#include <LibWeb/CSS/StyleValues/StyleValue.h>
+
+namespace Web::CSS {
+
+class ScrollFunctionStyleValue final : public StyleValueWithDefaultOperators<ScrollFunctionStyleValue> {
+public:
+    static ValueComparingNonnullRefPtr<ScrollFunctionStyleValue const> create(Scroller scroller, Axis axis)
+    {
+        return adopt_ref(*new ScrollFunctionStyleValue(scroller, axis));
+    }
+    virtual ~ScrollFunctionStyleValue() override = default;
+
+    virtual String to_string(SerializationMode) const override;
+    bool properties_equal(ScrollFunctionStyleValue const& other) const { return m_scroller == other.m_scroller && m_axis == other.m_axis; }
+
+    Scroller scroller() const { return m_scroller; }
+    Axis axis() const { return m_axis; }
+
+private:
+    explicit ScrollFunctionStyleValue(Scroller scroller, Axis axis)
+        : StyleValueWithDefaultOperators(Type::ScrollFunction)
+        , m_scroller(scroller)
+        , m_axis(axis)
+    {
+    }
+
+    Scroller m_scroller;
+    Axis m_axis;
+};
+
+}