* Electron version: 1.6.5
* Operating system: macOS Sierra

If you have a window with native tab bar to the top and you open a new window, it will open as separate window. But if you are in fullscreen mode, that new window will be attached as tab. Would it make sense to have API to force a window to open into an existing tab group or not? This would make it possible to give the user the choice of wether a window should open as tab or not independent from being in fullscreen mode or not.

Not even sure such API exists on macOS though.

/cc @tonyganch
atom/browser/native_window_mac.h
base::scoped_nsobject<AtomNSWindowDelegate> window_delegate_;
  
  id wheel_event_monitor_;
  
  base::scoped_nsobject<FullSizeContentView> content_view_;
  NativeBrowserView* browser_view_;
  std::vector<DraggableRegion> draggable_regions_;
  bool is_kiosk_;
  bool was_fullscreen_;
  bool zoom_to_page_width_;
  bool fullscreen_window_title_;
  NSInteger attention_request_id_;  
  
  NSApplicationPresentationOptions kiosk_options_;
  
  TitleBarStyle title_bar_style_;
  
  bool always_simple_fullscreen_;
  bool is_simple_fullscreen_;
  bool was_maximizable_;
  bool was_movable_;
  NSRect original_frame_;
  NSUInteger simple_fullscreen_mask_;
  
  NSApplicationPresentationOptions simple_fullscreen_options_;
  DISALLOW_COPY_AND_ASSIGN(NativeWindowMac);
};
}  
#endif