Remove redundant classes

Avalonia.sln

@@ -201,9 +201,9 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Avalonia.Dialogs", "src\Ava
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Avalonia.FreeDesktop", "src\Avalonia.FreeDesktop\Avalonia.FreeDesktop.csproj", "{4D36CEC8-53F2-40A5-9A37-79AAE356E2DA}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Avalonia.Controls.DataGrid.UnitTests", "tests\Avalonia.Controls.DataGrid.UnitTests\Avalonia.Controls.DataGrid.UnitTests.csproj", "{351337F5-D66F-461B-A957-4EF60BDB4BA6}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Avalonia.Controls.DataGrid.UnitTests", "tests\Avalonia.Controls.DataGrid.UnitTests\Avalonia.Controls.DataGrid.UnitTests.csproj", "{351337F5-D66F-461B-A957-4EF60BDB4BA6}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NativeEmbedSample", "samples\interop\NativeEmbedSample\NativeEmbedSample.csproj", "{3C84E04B-36CF-4D0D-B965-C26DD649D1F3}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "NativeEmbedSample", "samples\interop\NativeEmbedSample\NativeEmbedSample.csproj", "{3C84E04B-36CF-4D0D-B965-C26DD649D1F3}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Avalonia.Themes.Fluent", "src\Avalonia.Themes.Fluent\Avalonia.Themes.Fluent.csproj", "{C42D2FC1-A531-4ED4-84B9-89AEC7C962FC}"
 EndProject
@@ -211,8 +211,8 @@ Global
 	GlobalSection(SharedMSBuildProjectFiles) = preSolution
 		src\Shared\RenderHelpers\RenderHelpers.projitems*{3c4c0cb4-0c0f-4450-a37b-148c84ff905f}*SharedItemsImports = 13
 		src\Shared\RenderHelpers\RenderHelpers.projitems*{3e908f67-5543-4879-a1dc-08eace79b3cd}*SharedItemsImports = 5
-		src\Shared\PlatformSupport\PlatformSupport.projitems*{4488ad85-1495-4809-9aa4-ddfe0a48527e}*SharedItemsImports = 4
-		src\Shared\PlatformSupport\PlatformSupport.projitems*{7b92af71-6287-4693-9dcb-bd5b6e927e23}*SharedItemsImports = 4
+		src\Shared\PlatformSupport\PlatformSupport.projitems*{4488ad85-1495-4809-9aa4-ddfe0a48527e}*SharedItemsImports = 5
+		src\Shared\PlatformSupport\PlatformSupport.projitems*{7b92af71-6287-4693-9dcb-bd5b6e927e23}*SharedItemsImports = 5
 		src\Shared\RenderHelpers\RenderHelpers.projitems*{7d2d3083-71dd-4cc9-8907-39a0d86fb322}*SharedItemsImports = 5
 		src\Shared\PlatformSupport\PlatformSupport.projitems*{88060192-33d5-4932-b0f9-8bd2763e857d}*SharedItemsImports = 5
 		src\Shared\PlatformSupport\PlatformSupport.projitems*{e4d9629c-f168-4224-3f51-a5e482ffbc42}*SharedItemsImports = 13

src/Avalonia.Visuals/Media/TextFormatting/TextEndOfSegment.cs

@@ -1,17 +0,0 @@
-namespace Avalonia.Media.TextFormatting
-{
-    /// <summary>
-    /// Specialized text run used to mark the end of a segment, i.e., to end
-    /// the scope affected by a preceding TextModifier run.
-    /// </summary>
-    public class TextEndOfSegment : TextRun
-    {
-        public TextEndOfSegment(int textSourceLength)
-        {
-            TextSourceLength = textSourceLength;
-        }
-
-        /// <inheritdoc />
-        public override int TextSourceLength { get; }
-    }
-}

src/Avalonia.Visuals/Media/TextFormatting/TextHidden.cs

@@ -1,9 +0,0 @@
-namespace Avalonia.Media.TextFormatting
-{
-    /// <summary>
-    /// Specialized text run used to mark a range of hidden characters
-    /// </summary>
-    public class TextHidden : TextRun
-    {
-    }
-}

src/Avalonia.Visuals/Media/TextFormatting/TextModifier.cs

@@ -1,19 +0,0 @@
-namespace Avalonia.Media.TextFormatting
-{
-    /// <summary>
-    /// Specialized text run used to modify properties of text runs in its scope.
-    /// The scope extends to the next matching EndOfSegment text run (matching
-    /// because text modifiers may be nested), or to the next EndOfParagraph.
-    /// </summary>
-    public abstract class TextModifier : TextRun
-    {
-        /// <summary>
-        /// Modifies the properties of a text run.
-        /// </summary>
-        /// <param name="properties">Properties of a text run or the return value of
-        /// ModifyProperties for a nested text modifier.</param>
-        /// <returns>Returns the actual text run properties to be used for formatting,
-        /// subject to further modification by text modifiers at outer scopes.</returns>
-        public abstract TextRunProperties ModifyProperties(TextRunProperties properties);
-    }
-}