* 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 SetFullScreenable(bool fullscreenable) override;
  bool IsFullScreenable() override;
  void SetClosable(bool closable) override;
  bool IsClosable() override;
  void SetAlwaysOnTop(bool top, const std::string& level,
                      int relativeLevel, std::string* error) override;
  bool IsAlwaysOnTop() override;
  void Center() override;
  void Invalidate() override;
  void SetTitle(const std::string& title) override;
  std::string GetTitle() override;
  void FlashFrame(bool flash) override;
  void SetSkipTaskbar(bool skip) override;
  void SetSimpleFullScreen(bool simple_fullscreen) override;
  bool IsSimpleFullScreen() override;
  void SetKiosk(bool kiosk) override;
  bool IsKiosk() override;
  void SetBackgroundColor(const std::string& color_name) override;
  void SetHasShadow(bool has_shadow) override;
  bool HasShadow() override;
  void SetRepresentedFilename(const std::string& filename) override;
  std::string GetRepresentedFilename() override;
  void SetDocumentEdited(bool edited) override;
  bool IsDocumentEdited() override;
  void SetIgnoreMouseEvents(bool ignore, bool) override;
  void SetContentProtection(bool enable) override;
  void SetBrowserView(NativeBrowserView* browser_view) override;
  void SetParentWindow(NativeWindow* parent) override;
  gfx::NativeView GetNativeView() const override;
  gfx::NativeWindow GetNativeWindow() const override;