Fix some issues.

Runtime/async/timer.cs

             }
         }
 
-        public class TimerImpl : Timer, IComparable<TimerImpl> {
+        class TimerImpl : Timer, IComparable<TimerImpl> {
             float _deadline;
             readonly Action _callback;
             bool _done;

Runtime/editor/editor_window.cs

         }
         
         protected override int queryAntiAliasing() {
-            return Window.DefaultAntiAliasing;
+            return Window.defaultAntiAliasing;
         }
 
         protected override Vector2 queryWindowSize() {

Runtime/editor/surface.cs

             return this._antiAliasing;
         }
 
-        public EditorWindowSurface(DrawToTargetFunc drawToTargetFunc = null, int antiAliasing = Window.DefaultAntiAliasing) {
+        public EditorWindowSurface(DrawToTargetFunc drawToTargetFunc = null, int antiAliasing = Window.defaultAntiAliasing) {
             this._drawToTargetFunc = drawToTargetFunc;
             this._antiAliasing = antiAliasing;
         }
             return this._canvas;
         }
 
-        public GrSurface(Size size, float devicePixelRatio, MeshPool meshPool, int antiAliasing = Window.DefaultAntiAliasing) {
+        public GrSurface(Size size, float devicePixelRatio, MeshPool meshPool, int antiAliasing = Window.defaultAntiAliasing) {
             this.size = size;
             this.devicePixelRatio = devicePixelRatio;
             this._antiAliasing = antiAliasing;

Runtime/engine/UIWidgetsPanel.cs

         static Event _repaintEvent;
 
         [SerializeField] protected float devicePixelRatioOverride;
-        [SerializeField] protected int antiAliasingOverride = Window.DefaultAntiAliasing;
+        [SerializeField] protected int antiAliasingOverride = Window.defaultAntiAliasing;
         WindowAdapter _windowAdapter;
         Texture _texture;
         Vector2 _lastMouseMove;
         
         public int antiAliasing {
             get {
-                return this.antiAliasingOverride >= 0 ? this.antiAliasingOverride : Window.DefaultAntiAliasing;
+                return this.antiAliasingOverride >= 0 ? this.antiAliasingOverride : Window.defaultAntiAliasing;
             }
         }
 

Runtime/flow/raster_cache.cs

         public int antiAliasing {
             set { this._antiAliasing = value; }
         }
-        int _antiAliasing = Window.DefaultAntiAliasing;
+        int _antiAliasing = Window.defaultAntiAliasing;
 
         public MeshPool meshPool {
             set { this._meshPool = value; }

Runtime/ui/painting/canvas_impl.cs

     public class CommandBufferCanvas : RecorderCanvas {
         readonly PictureFlusher _flusher;
         
-        public CommandBufferCanvas(RenderTexture renderTexture, float devicePixelRatio, MeshPool meshPool, int antiAliasing = Window.DefaultAntiAliasing) 
+        public CommandBufferCanvas(RenderTexture renderTexture, float devicePixelRatio, MeshPool meshPool, int antiAliasing = Window.defaultAntiAliasing) 
             : base(new PictureRecorder()) {
             this._flusher = new PictureFlusher(renderTexture, devicePixelRatio, meshPool, antiAliasing);
         }

Runtime/ui/window.cs

 
         internal static Window _instance;
 
-        public const int DefaultAntiAliasing = 4;
+        public const int defaultAntiAliasing = 4;
 
         public float devicePixelRatio {
             get { return this._devicePixelRatio; }
             get { return this._antiAliasing; }
         }
 
-        protected int _antiAliasing = DefaultAntiAliasing;
+        protected int _antiAliasing = defaultAntiAliasing;
 
         public Size physicalSize {
             get { return this._physicalSize; }

Runtime/widgets/overscroll_indicator.cs

             }
 
             this._pullRecedeTimer =
-                new TimerProvider.TimerImpl(this._pullHoldTime, () => this._recede(this._pullDecayTime));
+                Window.instance.run(this._pullHoldTime, () => this._recede(this._pullDecayTime));
         }
 
         public void scrollEnd() {

Tests/Editor/CanvasAndLayers.cs

 
         static Texture2D texture6;
 
-        int _antiAliasing = Window.DefaultAntiAliasing;
+        int _antiAliasing = Window.defaultAntiAliasing;
 
         CanvasAndLayers() {
             this._options = new Action[] {