Now that we have a supported platform list of >= 10.10 we can use the `[NSStatusItem button]` instead of the hacks and tricks we use currently.
shell/browser/ui/tray_icon_cocoa.h
~TrayIconCocoa() override;
  void SetImage(const gfx::Image& image) override;
  void SetPressedImage(const gfx::Image& image) override;
  void SetToolTip(const std::string& tool_tip) override;
  void SetTitle(const std::string& title) override;
  std::string GetTitle() override;
  void SetHighlightMode(TrayIcon::HighlightMode mode) override;
  void SetIgnoreDoubleClickEvents(bool ignore) override;
  bool GetIgnoreDoubleClickEvents() override;
  void PopUpOnUI(AtomMenuModel* menu_model);
  void PopUpContextMenu(const gfx::Point& pos,
                        AtomMenuModel* menu_model) override;
  void SetContextMenu(AtomMenuModel* menu_model) override;
  gfx::Rect GetBounds() override;
 protected:
  
  void OnMenuWillClose() override;
 private:
  
  base::scoped_nsobject<StatusItemView> status_item_view_;
  
  base::scoped_nsobject<AtomMenuController> menu_;
  
  AtomMenuModel* menu_model_ = nullptr;  
  base::WeakPtrFactory<TrayIconCocoa> weak_factory_;
  DISALLOW_COPY_AND_ASSIGN(TrayIconCocoa);
};
}  
#endif