Fix namespace build break.

samples/ControlCatalog/Pages/AutoCompleteBoxPage.xaml.cs

@@ -9,6 +9,7 @@ using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Avalonia.Data.Converters;
+using Avalonia.Data;
 
 namespace ControlCatalog.Pages
 {

tests/Avalonia.Controls.UnitTests/ButtonTests.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Windows.Input;
+using Avalonia.Data;
 using Avalonia.Markup.Data;
 using Xunit;
 

tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs

@@ -8,6 +8,7 @@ using Avalonia.Collections;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
+using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Markup.Data;

tests/Avalonia.Controls.UnitTests/Primitives/ToggleButtonTests.cs

@@ -1,4 +1,5 @@
-using Avalonia.Markup.Data;
+using Avalonia.Data;
+using Avalonia.Markup.Data;
 using Avalonia.UnitTests;
 
 using Xunit;

tests/Avalonia.LeakTests/ControlTests.cs

@@ -185,7 +185,7 @@ namespace Avalonia.LeakTests
                         Content = new TextBox()
                     };
 
-                    var binding = new Avalonia.Markup.Data.Binding
+                    var binding = new Avalonia.Data.Binding
                     {
                         Path = "Name"
                     };