* 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
bool zoom_to_page_width() const { return zoom_to_page_width_; }
  bool fullscreen_window_title() const { return fullscreen_window_title_; }
  bool simple_fullscreen() const { return always_simple_fullscreen_; }
 protected:
  
  
  std::vector<gfx::Rect> CalculateNonDraggableRegions(
      const std::vector<DraggableRegion>& regions, int width, int height);
 private:
  
  gfx::Rect ContentBoundsToWindowBounds(const gfx::Rect& bounds) const;
  gfx::Rect WindowBoundsToContentBounds(const gfx::Rect& bounds) const;
  void UpdateDraggableRegions(
      content::RenderFrameHost* rfh,
      const std::vector<DraggableRegion>& regions) override;
  void InternalSetParentWindow(NativeWindow* parent, bool attach);
  void ShowWindowButton(NSWindowButton button);
  void InstallView();
  void UninstallView();
  
  
  void UpdateDraggableRegionViews(const std::vector<DraggableRegion>& regions);
  void RegisterInputEventObserver(content::RenderViewHost* host);
  void UnregisterInputEventObserver(content::RenderViewHost* host);
  base::scoped_nsobject<AtomNSWindow> window_;