add benchmark

src/Core/tests/Benchmarks/Benchmarks/VisualTreeBenchmarker.cs

@@ -0,0 +1,49 @@
+using BenchmarkDotNet.Attributes;
+using Microsoft.Maui.Controls;
+
+namespace Microsoft.Maui.Benchmarks
+{
+	[MemoryDiagnoser]
+	public class VisualTreeBenchmarker
+	{
+		static readonly View[] Views = [
+			new Border(), new BoxView(), new CarouselView(), new Grid(), new Entry(), new Picker(), new CollectionView(),
+			new CheckBox(), new DatePicker(), new Stepper(), new Slider(), new ActivityIndicator(), new Frame(),
+			new ContentView(), new ProgressBar(), new SearchBar(), new Switch(), new TimePicker(), new WebView(), new Button(),
+		];
+
+		private const int Iterations = 100;
+
+		[Benchmark]
+		public void GetVisualTreeElements()
+		{
+			var layout = new VerticalStackLayout();
+
+			for (int i = 0; i < Iterations; i++)
+			{
+				var childLayout = new VerticalStackLayout();
+
+				foreach (var view in Views)
+				{
+					childLayout.Add(view);
+
+					var grandchildLayout = new VerticalStackLayout();
+
+					foreach (var view2 in Views)
+					{
+						grandchildLayout.Add(view);
+						grandchildLayout.GetVisualTreeElements(grandchildLayout.Frame);
+					}
+
+					layout.Add(grandchildLayout);
+
+					childLayout.GetVisualTreeElements(childLayout.Frame);
+				}
+
+				layout.Add(childLayout);
+
+				layout.GetVisualTreeElements(layout.Frame);
+			}
+		}
+	}
+}