* 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
void Show() override;
  void ShowInactive() override;
  void Hide() override;
  bool IsVisible() override;
  bool IsEnabled() override;
  void Maximize() override;
  void Unmaximize() override;
  bool IsMaximized() override;
  void Minimize() override;
  void Restore() override;
  bool IsMinimized() override;
  void SetFullScreen(bool fullscreen) override;
  bool IsFullscreen() const override;
  void SetBounds(const gfx::Rect& bounds, bool animate = false) override;
  gfx::Rect GetBounds() override;
  void SetContentSizeConstraints(
      const extensions::SizeConstraints& size_constraints) override;
  void SetResizable(bool resizable) override;
  bool IsResizable() override;
  void SetMovable(bool movable) override;
  void SetAspectRatio(double aspect_ratio, const gfx::Size& extra_size)
    override;
  void PreviewFile(const std::string& path, const std::string& display_name)
    override;
  void CloseFilePreview() override;
  bool IsMovable() override;
  void SetMinimizable(bool minimizable) override;
  bool IsMinimizable() override;
  void SetMaximizable(bool maximizable) override;
  bool IsMaximizable() override;