explicitly delete our c++ window on quit

src/views/mac/SampleAppDelegate.mm

 #import "SampleAppDelegate.h"
 
 #include "SkApplication.h"
 
 @implementation SampleAppDelegate
 @synthesize fWindow, fView, fOptions;
 
 -(void) applicationDidFinishLaunching:(NSNotification *)aNotification {
     //Load specified skia views after launching
     fView.fOptionsDelegate = fOptions;
     [fWindow setAcceptsMouseMovedEvents:YES];
     [fOptions registerMenus:fView.fWind->getMenus()];
 }
 
 - (IBAction)toiPadSize:(id)sender {
     NSRect frame = NSMakeRect(fWindow.frame.origin.x, fWindow.frame.origin.y, 768, 1024);
     [fWindow setFrame:frame display:YES animate:YES];
 }
 
 - (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender {
+    [fView freeNativeWind];
     application_term();
     return NSTerminateNow;
 }
 
 @end