* Electron version: 1.4.15
* Operating system: Windows 10

### Actual behavior

Height is oversized by exactly 8px consistently (taskbar is set to small icons).

![Alt](https://raw.githubusercontent.com/adi518/electron-frameless-maximize-test/master/issue.jpg)

### How to reproduce

https://github.com/adi518/electron-frameless-maximize-test
atom/browser/native_window_views.cc
return window_->GetNativeWindow();
}
void NativeWindowViews::SetProgressBar(
    double progress, NativeWindow::ProgressState state) {
#if defined(OS_WIN)
  taskbar_host_.SetProgressBar(GetAcceleratedWidget(), progress, state);
#elif defined(USE_X11)
  if (unity::IsRunning()) {
    unity::SetProgressFraction(progress);
  }
#endif
}
void NativeWindowViews::SetOverlayIcon(const gfx::Image& overlay,