Make Beatmaps parsable as skins

osu.Game/Skinning/Skin.cs

@@ -1,12 +1,13 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using osu.Framework.Audio.Sample;
 using osu.Framework.Graphics;
 
 namespace osu.Game.Skinning
 {
-    public abstract class Skin
+    public abstract class Skin : IDisposable
     {
         public readonly SkinInfo SkinInfo;
 
@@ -20,5 +21,29 @@ namespace osu.Game.Skinning
         {
             SkinInfo = skin;
         }
+
+        #region Disposal
+
+        ~Skin()
+        {
+            Dispose(false);
+        }
+
+        public void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        private bool isDisposed;
+
+        protected virtual void Dispose(bool isDisposing)
+        {
+            if (isDisposed)
+                return;
+            isDisposed = true;
+        }
+
+        #endregion
     }
 }