add platform settings.

src/Avalonia.Windowing/PlatformSettings.cs

@@ -0,0 +1,11 @@
+using System;
+using Avalonia.Platform;
+
+namespace Avalonia.Windowing
+{
+    public class PlatformSettings : IPlatformSettings
+    {
+        public Size DoubleClickSize => new Size(4, 4);
+        public TimeSpan DoubleClickTime => TimeSpan.FromMilliseconds(200);
+    }
+}

src/Avalonia.Windowing/WIndowingPlatform.cs

@@ -89,6 +89,7 @@ namespace Avalonia.Windowing
                 .Bind<IMouseDevice>().ToConstant(new MouseDevice())
                 .Bind<IPlatformIconLoader>().ToConstant(new IconLoader())
                 .Bind<IStandardCursorFactory>().ToConstant(new CursorFactory())
+                .Bind<IPlatformSettings>().ToConstant(new PlatformSettings())
                 .Bind<IPlatformThreadingInterface>().ToConstant(this);
         }