fix mem leak tests for context menus.

src/Avalonia.Themes.Fluent/TextBox.xaml

@@ -14,6 +14,11 @@
     <StreamGeometry x:Key="TextBoxClearButtonData">M 11.416016,10 20,1.4160156 18.583984,0 10,8.5839846 1.4160156,0 0,1.4160156 8.5839844,10 0,18.583985 1.4160156,20 10,11.416015 18.583984,20 20,18.583985 Z</StreamGeometry>
     <StreamGeometry x:Key="PasswordBoxRevealButtonData">m10.051 7.0032c2.215 0 4.0105 1.7901 4.0105 3.9984s-1.7956 3.9984-4.0105 3.9984c-2.215 0-4.0105-1.7901-4.0105-3.9984s1.7956-3.9984 4.0105-3.9984zm0 1.4994c-1.3844 0-2.5066 1.1188-2.5066 2.499s1.1222 2.499 2.5066 2.499 2.5066-1.1188 2.5066-2.499-1.1222-2.499-2.5066-2.499zm0-5.0026c4.6257 0 8.6188 3.1487 9.7267 7.5613 0.10085 0.40165-0.14399 0.80877-0.54686 0.90931-0.40288 0.10054-0.81122-0.14355-0.91208-0.54521-0.94136-3.7492-4.3361-6.4261-8.2678-6.4261-3.9334 0-7.3292 2.6792-8.2689 6.4306-0.10063 0.40171-0.50884 0.64603-0.91177 0.54571s-0.648-0.5073-0.54737-0.90901c1.106-4.4152 5.1003-7.5667 9.728-7.5667z</StreamGeometry>
     <StreamGeometry x:Key="PasswordBoxHideButtonData">m0.21967 0.21965c-0.26627 0.26627-0.29047 0.68293-0.07262 0.97654l0.07262 0.08412 4.0346 4.0346c-1.922 1.3495-3.3585 3.365-3.9554 5.7495-0.10058 0.4018 0.14362 0.8091 0.54543 0.9097 0.40182 0.1005 0.80909-0.1436 0.90968-0.5455 0.52947-2.1151 1.8371-3.8891 3.5802-5.0341l1.8096 1.8098c-0.70751 0.7215-1.1438 1.71-1.1438 2.8003 0 2.2092 1.7909 4 4 4 1.0904 0 2.0788-0.4363 2.8004-1.1438l5.9193 5.9195c0.2929 0.2929 0.7677 0.2929 1.0606 0 0.2663-0.2662 0.2905-0.6829 0.0726-0.9765l-0.0726-0.0841-6.1135-6.1142 0.0012-0.0015-1.2001-1.1979-2.8699-2.8693 2e-3 -8e-4 -2.8812-2.8782 0.0012-0.0018-1.1333-1.1305-4.3064-4.3058c-0.29289-0.29289-0.76777-0.29289-1.0607 0zm7.9844 9.0458 3.5351 3.5351c-0.45 0.4358-1.0633 0.704-1.7392 0.704-1.3807 0-2.5-1.1193-2.5-2.5 0-0.6759 0.26824-1.2892 0.7041-1.7391zm1.7959-5.7655c-1.0003 0-1.9709 0.14807-2.8889 0.425l1.237 1.2362c0.5358-0.10587 1.0883-0.16119 1.6519-0.16119 3.9231 0 7.3099 2.6803 8.2471 6.4332 0.1004 0.4018 0.5075 0.6462 0.9094 0.5459 0.4019-0.1004 0.6463-0.5075 0.5459-0.9094-1.103-4.417-5.0869-7.5697-9.7024-7.5697zm0.1947 3.5093 3.8013 3.8007c-0.1018-2.0569-1.7488-3.7024-3.8013-3.8007z</StreamGeometry>
+    <ContextMenu x:Key="DefaultTextBoxContextMenu">
+      <MenuItem Header="Cut" Command="{Binding $parent[TextBox].Cut}" IsEnabled="{Binding $parent[TextBox].CanCut}" InputGesture="{x:Static TextBox.CutGesture}" />
+      <MenuItem Header="Copy" Command="{Binding $parent[TextBox].Copy}" IsEnabled="{Binding $parent[TextBox].CanCopy}" InputGesture="{x:Static TextBox.CopyGesture}"/>
+      <MenuItem Header="Paste" Command="{Binding $parent[TextBox].Paste}" IsEnabled="{Binding $parent[TextBox].CanPaste}" InputGesture="{x:Static TextBox.PasteGesture}"/>
+    </ContextMenu>
   </Styles.Resources>
 
   <Style Selector="TextBox">

tests/Avalonia.LeakTests/ControlTests.cs

@@ -427,6 +427,15 @@ namespace Avalonia.LeakTests
         {
             using (Start())
             {
+                // Context menu in resources means the baseline may not be 0.
+                var initialMenuCount = 0;
+                var initialMenuItemCount = 0;
+                dotMemory.Check(memory =>
+                {
+                    initialMenuCount = memory.GetObjects(where => where.Type.Is<ContextMenu>()).ObjectsCount;
+                    initialMenuItemCount = memory.GetObjects(where => where.Type.Is<MenuItem>()).ObjectsCount;
+                });
+                
                 void AttachShowAndDetachContextMenu(Control control)
                 {
                     var contextMenu = new ContextMenu
@@ -453,9 +462,9 @@ namespace Avalonia.LeakTests
 
                 Mock.Get(window.PlatformImpl).ResetCalls();
                 dotMemory.Check(memory =>
-                    Assert.Equal(0, memory.GetObjects(where => where.Type.Is<ContextMenu>()).ObjectsCount));
+                    Assert.Equal(initialMenuCount, memory.GetObjects(where => where.Type.Is<ContextMenu>()).ObjectsCount));
                 dotMemory.Check(memory =>
-                    Assert.Equal(0, memory.GetObjects(where => where.Type.Is<MenuItem>()).ObjectsCount));
+                    Assert.Equal(initialMenuItemCount, memory.GetObjects(where => where.Type.Is<MenuItem>()).ObjectsCount));
             }
         }