* **Electron Version** (output of `node_modules/.bin/electron --version`):
  * 4.0.4
* **Operating System** (Platform and Version):
  * macOS 10.14.3
* **Last known working Electron version** (if applicable):
  * unknown

### Expected Behavior
Setting a MenuItem to `visible: false` will hide it from the menu but **not** disable it.

See documentation https://electronjs.org/docs/api/menu-item

### Actual behavior
MenuItem is hidden AND disabled

### To Reproduce
https://github.com/aaronraimist/electron-quick-start/tree/visible-false

There should be one menu item visible (zoomin) and zoom out should also work but it doesn't.
(my issue is with zoomin but since that is kind of broken I did the demo with zoomout)

Menu code looks like
```
const template = [
  {
    label: 'View',
    submenu: [
	  { role: 'zoomin' },
      { role: 'zoomout', visible: false },
    ],
  }
]
```

```sh
# Clone this repository
git clone https://github.com/electron/electron-quick-start
# Go into the repository
cd electron-quick-start
# Checkout branch
git checkout visible-false
# Install dependencies
npm install
# Run the app
npm start
```

### Additional Information

I'm trying to work around https://github.com/electron/electron/issues/15496 by creating two menu items, one visible and one invisible but it doesn't work. See https://github.com/vector-im/riot-web/pull/8381
atom/browser/ui/atom_menu_model.h
virtual void OnMenuWillShow() {}
    
    virtual void OnMenuWillClose() {}
  };
  explicit AtomMenuModel(Delegate* delegate);
  ~AtomMenuModel() override;
  void AddObserver(Observer* obs) { observers_.AddObserver(obs); }
  void RemoveObserver(Observer* obs) { observers_.RemoveObserver(obs); }
  void SetRole(int index, const base::string16& role);
  base::string16 GetRoleAt(int index);
  bool GetAcceleratorAtWithParams(int index,
                                  bool use_default_accelerator,
                                  ui::Accelerator* accelerator) const;
  bool ShouldRegisterAcceleratorAt(int index) const;
  
  void MenuWillClose() override;
  void MenuWillShow() override;
  using SimpleMenuModel::GetSubmenuModelAt;
  AtomMenuModel* GetSubmenuModelAt(int index);
 private:
  Delegate* delegate_;  
  std::map<int, base::string16> roles_;  
  base::ObserverList<Observer> observers_;
  DISALLOW_COPY_AND_ASSIGN(AtomMenuModel);
};
}  
#endif