* 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/api/atom_api_window.h
bool IsFullscreen();
  void SetBounds(const gfx::Rect& bounds, mate::Arguments* args);
  gfx::Rect GetBounds();
  void SetSize(int width, int height, mate::Arguments* args);
  std::vector<int> GetSize();
  void SetContentSize(int width, int height, mate::Arguments* args);
  std::vector<int> GetContentSize();
  void SetContentBounds(const gfx::Rect& bounds, mate::Arguments* args);
  gfx::Rect GetContentBounds();
  void SetMinimumSize(int width, int height);
  std::vector<int> GetMinimumSize();
  void SetMaximumSize(int width, int height);
  std::vector<int> GetMaximumSize();
  void SetSheetOffset(double offsetY, mate::Arguments* args);
  void SetResizable(bool resizable);
  bool IsResizable();
  void SetMovable(bool movable);
  bool IsMovable();
  void SetMinimizable(bool minimizable);
  bool IsMinimizable();
  void SetMaximizable(bool maximizable);
  bool IsMaximizable();
  void SetFullScreenable(bool fullscreenable);
  bool IsFullScreenable();
  void SetClosable(bool closable);
  bool IsClosable();
  void SetAlwaysOnTop(bool top, mate::Arguments* args);
  bool IsAlwaysOnTop();
  void Center();
  void SetPosition(int x, int y, mate::Arguments* args);