### Preflight Checklist
* [x] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
* [x] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md) that this project adheres to.
* [x] I have searched the issue tracker for an issue that matches the one I want to file, without success.

### Issue Details

* **Electron Version:**
  * 6.0.0-beta.15
* **Operating System:**
  * Windows 10 64bit
* **Last Known Working Electron version:**
  * 5.0.8

### Expected Behavior
The window restores its size to what it used to be

### Actual Behavior
The window is shown in the smallest size

### To Reproduce
1) Maximize Window
2) Minimize Window
3) Restore Window (click on the icon in the taskbar)
4) Unmaximize Window

### Screenshots
![grafik](https://user-images.githubusercontent.com/10595986/61781949-84f18100-ae05-11e9-8983-17edb536427f.png)


shell/browser/native_window_views_win.cc
if (GetWindowPlacement(GetAcceleratedWidget(), &wp)) {
        last_normal_placement_bounds_ = gfx::Rect(wp.rcNormalPosition);
      }
      NotifyWindowMinimize();
      break;
    case SIZE_RESTORED:
      switch (last_window_state_) {
        case ui::SHOW_STATE_MAXIMIZED:
          last_window_state_ = ui::SHOW_STATE_NORMAL;
          NotifyWindowUnmaximize();
          if (!has_frame()) {
            TriggerNCCalcSize(GetAcceleratedWidget());
          }
          break;
        case ui::SHOW_STATE_MINIMIZED:
          if (IsFullscreen()) {
            last_window_state_ = ui::SHOW_STATE_FULLSCREEN;
            NotifyWindowEnterFullScreen();
          } else {
            last_window_state_ = ui::SHOW_STATE_NORMAL;
            NotifyWindowRestore();
          }
          break;
        default:
          break;
      }
      break;
  }
}
void NativeWindowViews::SetForwardMouseMessages(bool forward) {