Fix memory leak for Win & Mac

src/macos/window.rs

@@ -71,7 +71,6 @@ impl WindowInner {
     pub(super) fn close(&self) {
         if self.open.get() {
             self.open.set(false);
-
             unsafe {
                 // Take back ownership of the NSView's Rc<WindowState>
                 let state_ptr: *const c_void = *(*self.ns_view).get_ivar(BASEVIEW_STATE_IVAR);
@@ -87,6 +86,15 @@ impl WindowInner {
                     msg_send![class!(NSNotificationCenter), defaultCenter];
                 let () = msg_send![notification_center, removeObserver:self.ns_view];
 
+                // Ensure all subviews are detached and released
+                let subviews: id = msg_send![self.ns_view, subviews];
+                let count: usize = msg_send![subviews, count];
+                for i in 0..count {
+                    let subview: id = msg_send![subviews, objectAtIndex: i];
+                    subview.removeFromSuperview();
+                    let () = msg_send![subview, release];
+                }
+
                 drop(window_state);
 
                 // Close the window if in non-parented mode

src/win/window.rs

@@ -76,6 +76,7 @@ impl WindowHandle {
         if let Some(hwnd) = self.hwnd.take() {
             unsafe {
                 PostMessageW(hwnd, BV_WINDOW_MUST_CLOSE, 0, 0);
+                DestroyWindow(hwnd);
             }
         }
     }