fix implementation of maxclientsize osx.

native/Avalonia.Native/inc/avalonia-native.h

@@ -188,7 +188,6 @@ AVNCOM(IAvnWindowBase, 02) : IUnknown
     virtual HRESULT Close() = 0;
     virtual HRESULT Activate () = 0;
     virtual HRESULT GetClientSize(AvnSize*ret) = 0;
-    virtual HRESULT GetMaxClientSize(AvnSize* ret) = 0;
     virtual HRESULT GetScaling(double*ret)=0;
     virtual HRESULT SetMinMaxSize(AvnSize minSize, AvnSize maxSize) = 0;
     virtual HRESULT Resize(double width, double height) = 0;

native/Avalonia.Native/src/OSX/Screens.mm

@@ -38,7 +38,7 @@ class Screens : public ComSingleObject<IAvnScreens, &IID_IAvnScreens>
             ret->WorkingArea.Height = [screen visibleFrame].size.height;
             ret->WorkingArea.Width = [screen visibleFrame].size.width;
             
-            ret->PixelDenisty = [screen backingScaleFactor];
+            ret->PixelDensity = [screen backingScaleFactor];
             
             ret->Primary = index == 0;
             

native/Avalonia.Native/src/OSX/window.mm

@@ -54,7 +54,6 @@ public:
     FORWARD_IUNKNOWN()
     virtual ~WindowBaseImpl()
     {
-        NSDebugLog(@"~WindowBaseImpl()");
         View = NULL;
         Window = NULL;
     }
@@ -161,22 +160,6 @@ public:
         }
     }
     
-    virtual HRESULT GetMaxClientSize(AvnSize* ret) override
-    {
-        @autoreleasepool
-        {
-            if(ret == nullptr)
-                return E_POINTER;
-            
-            auto size = [NSScreen.screens objectAtIndex:0].frame.size;
-            
-            ret->Height = size.height;
-            ret->Width = size.width;
-            
-            return S_OK;
-        }
-    }
-    
     virtual HRESULT GetScaling (double* ret) override
     {
         @autoreleasepool
@@ -416,8 +399,8 @@ private:
     INHERIT_INTERFACE_MAP(WindowBaseImpl)
     INTERFACE_MAP_ENTRY(IAvnWindow, IID_IAvnWindow)
     END_INTERFACE_MAP()
-    virtual ~WindowImpl(){
-        NSDebugLog(@"~WindowImpl");
+    virtual ~WindowImpl()
+    {
     }
     
     ComPtr<IAvnWindowEvents> WindowEvents;
@@ -664,10 +647,8 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
 
 - (void)dealloc
 {
-    NSDebugLog(@"AvnView dealloc");
 }
 
-
 - (void)onClosed
 {
     _parent = NULL;
@@ -1067,7 +1048,6 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
 
 - (void)dealloc
 {
-    NSDebugLog(@"AvnWindow dealloc");
 }
 
 - (void)pollModalSession:(nonnull NSModalSession)session

src/Avalonia.Native/WindowImplBase.cs

@@ -306,7 +306,8 @@ namespace Avalonia.Native
             _native.BeginMoveDrag();
         }
 
-        public Size MaxClientSize => _native.GetMaxClientSize().ToAvaloniaSize();
+        public Size MaxClientSize => Screen.AllScreens.Select(s => s.Bounds.Size.ToSize(s.PixelDensity))
+            .OrderByDescending(x => x.Width + x.Height).FirstOrDefault();
 
         public void SetTopmost(bool value)
         {