Add a benchmark case for affects render.

tests/Avalonia.Benchmarks/Visuals/VisualAffectsRenderBenchmarks.cs

@@ -0,0 +1,45 @@
+using Avalonia.Controls;
+using Avalonia.Media;
+using BenchmarkDotNet.Attributes;
+
+namespace Avalonia.Benchmarks.Visuals;
+
+[MemoryDiagnoser]
+public class VisualAffectsRenderBenchmarks
+{
+    private readonly TestVisual _target;
+    private readonly IPen _pen;
+        
+    public VisualAffectsRenderBenchmarks()
+    {
+        _target = new TestVisual();
+        _pen = new Pen(Brushes.Black);
+    }
+        
+    [Benchmark]
+    public void SetPropertyThatAffectsRender()
+    {
+        _target.Pen = _pen;
+        _target.Pen = null;
+    }
+
+    private class TestVisual : Visual
+    {
+        /// <summary>
+        /// Defines the <see cref="Pen"/> property.
+        /// </summary>
+        public static readonly StyledProperty<IPen> PenProperty =
+            AvaloniaProperty.Register<Border, IPen>(nameof(Pen));
+            
+        public IPen Pen
+        {
+            get { return GetValue(PenProperty); }
+            set { SetValue(PenProperty, value); }
+        }
+
+        static TestVisual()
+        {
+            AffectsRender<TestVisual>(PenProperty);
+        }
+    }
+}