Use DrawSize instead of Size whereever Size was previously read due to framework changes.

Note, that this was just stupid replacement. Many components will likely want to actually read Size and not DrawSize. We may want to do a pass over this at some point, but for now everything is working like this. (Old behavior.)

osu.Game/Graphics/Processing/RatioAdjust.cs

@@ -20,7 +20,7 @@ namespace osu.Game.Graphics.Processing
         protected override void Update()
         {
             base.Update();
-            Vector2 parent = Parent.Size;
+            Vector2 parent = Parent.DrawSize;
 
             Scale = new Vector2(Math.Min(parent.Y / 768f, parent.X / 1024f));
             Size = new Vector2(1 / Scale.X);