views: mac: Fix frameless window behavior (fixes issue #3189)

Frameless windows now display as expected. Default traffic light buttons can
optionally be shown at configurable vertical position. Layout respects text
direction.

libcef/browser/views/native_widget_mac.h

@@ -0,0 +1,37 @@
+// Copyright 2023 The Chromium Embedded Framework Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be found
+// in the LICENSE file.
+
+#ifndef CEF_LIBCEF_BROWSER_VIEWS_NATIVE_WIDGET_MAC_H_
+#define CEF_LIBCEF_BROWSER_VIEWS_NATIVE_WIDGET_MAC_H_
+#pragma once
+
+#include "third_party/abseil-cpp/absl/types/optional.h"
+#include "ui/views/widget/native_widget_mac.h"
+
+class CefNativeWidgetMac : public views::NativeWidgetMac {
+ public:
+  CefNativeWidgetMac(views::internal::NativeWidgetDelegate* delegate,
+                     bool is_frameless,
+                     bool with_window_buttons,
+                     absl::optional<float> title_bar_height);
+  ~CefNativeWidgetMac() override = default;
+
+  CefNativeWidgetMac(const CefNativeWidgetMac&) = delete;
+  CefNativeWidgetMac& operator=(const CefNativeWidgetMac&) = delete;
+
+ protected:
+  // NativeWidgetMac:
+  NativeWidgetMacNSWindow* CreateNSWindow(
+      const remote_cocoa::mojom::CreateWindowParams* params) override;
+
+  void GetWindowFrameTitlebarHeight(bool* override_titlebar_height,
+                                    float* titlebar_height) override;
+
+ private:
+  const bool is_frameless_;
+  const bool with_window_buttons_;
+  const absl::optional<float> title_bar_height_;
+};
+
+#endif  // CEF_LIBCEF_BROWSER_VIEWS_NATIVE_WIDGET_MAC_H_