* Electron version: 1.4.14
* Operating system: Windows 8.1

### Expected behavior

A fullscreen transparent window should be transparent.

### Actual behavior

The window is not transparent (has a white background).

### How to reproduce

```
electron.app.on("ready", function () {
    var win = new BrowserWindow({
        show: true,
        frame: false,
        fullscreen: true,
        transparent: true
    });
});
```

Refs https://github.com/electron/electron/issues/8321#issuecomment-273615701


atom/browser/native_window_views.cc
if (is_modal())
      state_atom_list.push_back(GetAtom("_NET_WM_STATE_MODAL"));
  }
  ui::SetAtomArrayProperty(GetAcceleratedWidget(), "_NET_WM_STATE", "ATOM",
                           state_atom_list);
  
  if (!window_type.empty())
    SetWindowType(GetAcceleratedWidget(), window_type);
#endif
  
  SetLayoutManager(new MenuLayout(this, kMenuBarHeight));
  AddChildView(web_view_);
#if defined(OS_WIN)
  if (!has_frame()) {
    
    
    DWORD frame_style = WS_CAPTION;
    if (resizable_)
      frame_style |= WS_THICKFRAME;
    if (minimizable_)
      frame_style |= WS_MINIMIZEBOX;
    if (maximizable_)
      frame_style |= WS_MAXIMIZEBOX;
    
    if (!thick_frame_)
      frame_style &= ~(WS_THICKFRAME | WS_CAPTION);
    ::SetWindowLong(GetAcceleratedWidget(), GWL_STYLE, frame_style);
  }
  LONG ex_style = ::GetWindowLong(GetAcceleratedWidget(), GWL_EXSTYLE);