* 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
views::FocusManager* focus_manager = GetFocusManager();
  accelerator_table_.clear();
  focus_manager->UnregisterAccelerators(this);
  
  accelerator_util::GenerateAcceleratorTable(&accelerator_table_, menu_model);
  accelerator_util::AcceleratorTable::const_iterator iter;
  for (iter = accelerator_table_.begin();
       iter != accelerator_table_.end();
       ++iter) {
    focus_manager->RegisterAccelerator(
        iter->first, ui::AcceleratorManager::kNormalPriority, this);
  }
}
ui::WindowShowState NativeWindowViews::GetRestoredState() {
  if (IsMaximized())
    return ui::SHOW_STATE_MAXIMIZED;
  if (IsFullscreen())
    return ui::SHOW_STATE_FULLSCREEN;
  return ui::SHOW_STATE_NORMAL;
}
NativeWindow* NativeWindow::Create(
    brightray::InspectableWebContents* inspectable_web_contents,
    const mate::Dictionary& options,
    NativeWindow* parent) {
  return new NativeWindowViews(inspectable_web_contents, options, parent);
}
}