* Electron version: 1.7.6
* Operating system: MacOS High Sierra GM

### Expected behavior

Title bar should not be invisible

![screen shot 2017-09-14 at 11 22 04 am](https://user-images.githubusercontent.com/320654/30441406-f34fe61a-993e-11e7-8592-244e50a92bb9.png)

### Actual behavior

Title bar is invisible

### How to reproduce
```
  mainWindow = new BrowserWindow({
      vibrancy: 'light',
      titleBarStyle: 'hiddenInset',
      width: 800,
      height: 600
  })
```

```
 $ git clone git@github.com:gerges/electron-quick-start.git -b  issue/invisible-titlebar
 $ npm install
 $ npm run start
```

atom/browser/native_window_mac.h
base::scoped_nsobject<AtomNSWindowDelegate> window_delegate_;
  
  id wheel_event_monitor_;
  
  base::scoped_nsobject<FullSizeContentView> content_view_;
  NativeBrowserView* browser_view_;
  std::vector<DraggableRegion> draggable_regions_;
  bool is_kiosk_;
  bool was_fullscreen_;
  bool zoom_to_page_width_;
  bool fullscreen_window_title_;
  NSInteger attention_request_id_;  
  
  NSApplicationPresentationOptions kiosk_options_;
  
  TitleBarStyle title_bar_style_;
  
  bool always_simple_fullscreen_;
  bool is_simple_fullscreen_;
  bool was_maximizable_;
  bool was_movable_;
  NSRect original_frame_;
  NSUInteger simple_fullscreen_mask_;
  
  NSApplicationPresentationOptions simple_fullscreen_options_;
  DISALLOW_COPY_AND_ASSIGN(NativeWindowMac);
};
}  
#endif