Removed duplicated code

src/Avalonia.Visuals/Rendering/ManagedDeferredRendererLock.cs

@@ -6,46 +6,6 @@ namespace Avalonia.Rendering
 {
     public class ManagedDeferredRendererLock : DisposableLock, IDeferredRendererLock
     {
-        private readonly object _lock = new object();
-
-        /// <summary>
-        /// Tries to lock the target surface or window
-        /// </summary>
-        /// <returns>IDisposable if succeeded to obtain the lock</returns>
-        public IDisposable TryLock()
-        {
-            if (Monitor.TryEnter(_lock))
-                return new UnlockDisposable(_lock);
-            return null;
-        }
-
-        /// <summary>
-        /// Enters a waiting lock, only use from platform code, not from the renderer
-        /// </summary>
-        public IDisposable Lock()
-        {
-            Monitor.Enter(_lock);
-            return new UnlockDisposable(_lock);
-        }
-
-        private sealed class UnlockDisposable : IDisposable
-        {
-            private object _lock;
-
-            public UnlockDisposable(object @lock)
-            {
-                _lock = @lock;
-            }
-
-            public void Dispose()
-            {
-                object @lock = Interlocked.Exchange(ref _lock, null);
-
-                if (@lock != null)
-                {
-                    Monitor.Exit(@lock);
-                }
-            }
-        }
+       
     }
 }