Move field.

src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlLayoutViewModel.cs

@@ -12,6 +12,7 @@ namespace Avalonia.Diagnostics.ViewModels
         private Thickness _borderThickness;
         private Thickness _paddingThickness;
         private string _sizeText;
+        private bool _updatingFromControl;
 
         public Thickness MarginThickness
         {
@@ -66,8 +67,6 @@ namespace Avalonia.Diagnostics.ViewModels
             UpdateSize();
         }
 
-        private bool _updatingFromControl;
-
         protected override void OnPropertyChanged(PropertyChangedEventArgs e)
         {
             base.OnPropertyChanged(e);