Fix CA1852

OpenRA.Platforms.Default/DummySoundEngine.cs

@@ -61,12 +61,12 @@ namespace OpenRA.Platforms.Default
 		public void Dispose() { }
 	}
 
-	class NullSoundSource : ISoundSource
+	sealed class NullSoundSource : ISoundSource
 	{
 		public void Dispose() { }
 	}
 
-	class NullSound : ISound
+	sealed class NullSound : ISound
 	{
 		public float Volume { get; set; }
 		public float SeekPosition => 0;

OpenRA.Platforms.Default/MultiTapDetection.cs

@@ -42,7 +42,7 @@ namespace OpenRA.Platforms.Default
 		}
 	}
 
-	class TapHistory
+	sealed class TapHistory
 	{
 		public (DateTime Time, int2 Location) FirstRelease, SecondRelease, ThirdRelease;
 

OpenRA.Platforms.Default/OpenAlSoundEngine.cs

@@ -36,7 +36,7 @@ namespace OpenRA.Platforms.Default
 			return defaultDevices.Concat(physicalDevices).ToArray();
 		}
 
-		class PoolSlot
+		sealed class PoolSlot
 		{
 			public bool IsActive;
 			public int FrameStarted;
@@ -386,7 +386,7 @@ namespace OpenRA.Platforms.Default
 		}
 	}
 
-	class OpenAlSoundSource : ISoundSource
+	sealed class OpenAlSoundSource : ISoundSource
 	{
 		uint buffer;
 		bool disposed;
@@ -401,7 +401,7 @@ namespace OpenRA.Platforms.Default
 			AL10.alBufferData(buffer, OpenAlSoundEngine.MakeALFormat(channels, sampleBits), data, byteCount, sampleRate);
 		}
 
-		protected virtual void Dispose(bool disposing)
+		void Dispose(bool _)
 		{
 			if (!disposed)
 			{
@@ -538,7 +538,7 @@ namespace OpenRA.Platforms.Default
 		}
 	}
 
-	class OpenAlAsyncLoadSound : OpenAlSound
+	sealed class OpenAlAsyncLoadSound : OpenAlSound
 	{
 		static readonly byte[] SilentData = new byte[2];
 		readonly CancellationTokenSource cts = new();

OpenRA.Platforms.Default/Sdl2Input.cs

@@ -16,7 +16,7 @@ using SDL2;
 
 namespace OpenRA.Platforms.Default
 {
-	class Sdl2Input
+	sealed class Sdl2Input
 	{
 		MouseButton lastButtonBits = MouseButton.None;
 

OpenRA.Platforms.Default/Shader.cs

@@ -16,7 +16,7 @@ using System.Text;
 
 namespace OpenRA.Platforms.Default
 {
-	class Shader : ThreadAffine, IShader
+	sealed class Shader : ThreadAffine, IShader
 	{
 		public const int VertexPosAttributeIndex = 0;
 		public const int TexCoordAttributeIndex = 1;
@@ -29,7 +29,7 @@ namespace OpenRA.Platforms.Default
 		readonly Queue<int> unbindTextures = new();
 		readonly uint program;
 
-		protected static uint CompileShaderObject(int type, string name)
+		static uint CompileShaderObject(int type, string name)
 		{
 			var ext = type == OpenGL.GL_VERTEX_SHADER ? "vert" : "frag";
 			var filename = Path.Combine(Platform.EngineDir, "glsl", name + "." + ext);

OpenRA.Platforms.Default/ThreadedGraphicsContext.cs

@@ -155,7 +155,7 @@ namespace OpenRA.Platforms.Default
 					verticesPool.Push(vertices);
 		}
 
-		class Message
+		sealed class Message
 		{
 			public Message(ThreadedGraphicsContext device)
 			{
@@ -450,7 +450,7 @@ namespace OpenRA.Platforms.Default
 		}
 	}
 
-	class ThreadedFrameBuffer : IFrameBuffer
+	sealed class ThreadedFrameBuffer : IFrameBuffer
 	{
 		readonly ThreadedGraphicsContext device;
 		readonly Func<ITexture> getTexture;
@@ -500,7 +500,7 @@ namespace OpenRA.Platforms.Default
 		}
 	}
 
-	class ThreadedVertexBuffer : IVertexBuffer<Vertex>
+	sealed class ThreadedVertexBuffer : IVertexBuffer<Vertex>
 	{
 		readonly ThreadedGraphicsContext device;
 		readonly Action bind;
@@ -563,7 +563,7 @@ namespace OpenRA.Platforms.Default
 		}
 	}
 
-	class ThreadedTexture : ITextureInternal
+	sealed class ThreadedTexture : ITextureInternal
 	{
 		readonly ThreadedGraphicsContext device;
 		readonly Func<object> getScaleFilter;
@@ -658,7 +658,7 @@ namespace OpenRA.Platforms.Default
 		}
 	}
 
-	class ThreadedShader : IShader
+	sealed class ThreadedShader : IShader
 	{
 		readonly ThreadedGraphicsContext device;
 		readonly Action prepareRender;