Support window resizing

Ryujinx.Graphics.GAL/IWindow.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace Ryujinx.Graphics.GAL
 {
     public interface IWindow
@@ -9,5 +7,7 @@ namespace Ryujinx.Graphics.GAL
         void QueueTexture(ITexture texture, ImageCrop crop, object context);
 
         void RegisterTextureReleaseCallback(TextureReleaseCallback callback);
+
+        void SetSize(int width, int height);
     }
 }