Hack dev tools to work again.

Need to fix the root layout problem that hangs it though.

Perspex.Controls/TopLevel.cs

@@ -146,6 +146,12 @@ namespace Perspex.Controls
             return Disposable.Create(() => this.autoSizing = false);
         }
 
+        protected override Size ArrangeOverride(Size finalSize)
+        {
+            this.PlatformImpl.ClientSize = finalSize;
+            return base.ArrangeOverride(finalSize);
+        }
+
         protected void ExecuteLayoutPass()
         {
             this.LayoutManager.ExecuteLayoutPass();

Perspex.Diagnostics/DevTools.cs

@@ -118,6 +118,10 @@ namespace Perspex.Diagnostics
             {
                 Window window = new Window
                 {
+                    // HACK: Set width and height here as a quick fix as there's a problem with 
+                    // the dev tools window hanging when it's set to auto-size.
+                    Width = 800,
+                    Height = 600,
                     Content = new DevTools
                     {
                         Root = (Window)sender,