* 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 defined(OS_WIN)
  if (has_frame())
    return ::GetWindowLong(GetAcceleratedWidget(), GWL_STYLE) & WS_THICKFRAME;
  else
    return CanResize();
#else
  return CanResize();
#endif
}
void NativeWindowViews::SetMovable(bool movable) {
  movable_ = movable;
}
bool NativeWindowViews::IsMovable() {
#if defined(OS_WIN)
  return movable_;
#else
  return true;  
#endif
}
void NativeWindowViews::SetMinimizable(bool minimizable) {
#if defined(OS_WIN)
  FlipWindowStyle(GetAcceleratedWidget(), minimizable, WS_MINIMIZEBOX);
#endif
  minimizable_ = minimizable;
}
bool NativeWindowViews::IsMinimizable() {