mac: cefclient: Fix zombie NSWindow object on exit (fixes #3602)

- Don't create a TempWindow when using Views.
- Don't call `close` on an NSWindow that is never opened.

tests/cefclient/browser/root_window_manager.cc

@@ -141,8 +141,9 @@ scoped_refptr<RootWindow> RootWindowManager::CreateRootWindowAsPopup(
 
   SanityCheckWindowConfig(is_devtools, use_views, use_alloy_style, with_osr);
 
-  if (!temp_window_) {
-    // TempWindow must be created on the UI thread.
+  if (!temp_window_ && !use_views) {
+    // TempWindow must be created on the UI thread. It is only used with
+    // native (non-Views) parent windows.
     temp_window_.reset(new TempWindow());
   }
 

tests/cefclient/browser/temp_window_mac.mm

@@ -29,7 +29,7 @@ class TempWindowMacImpl {
   }
   ~TempWindowMacImpl() {
     DCHECK(window_);
-    [window_ close];
+    window_ = nil;
   }
 
  private: