### 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.3
* **Operating System:**
  * Windows 10 (1809)
* **Last Known Working Electron version:**:
  * 5.0.1

### Expected Behavior
Dragging your mouse to the bottom of the screen with a maximized frameless window and a hidden Windows taskbar should make the taskbar appear.

### Actual Behavior
The taskbar does not appear.

### To Reproduce

* Ensure you have Taskbar hiding enabled
![image](https://user-images.githubusercontent.com/144914/57793291-d12d9000-76f5-11e9-8c63-178e928a5358.png)

```sh
$ git clone https://github.com/adill/electron-quick-start -b no-taskbar-unhide
$ npm install
$ npm start || electron .
```

* Move your mouse to the bottom of the screen

### Screenshots

### Additional Information

atom/browser/native_window_views_win.cc
if (GetWindowPlacement(GetAcceleratedWidget(), &wp)) {
        last_normal_placement_bounds_ = gfx::Rect(wp.rcNormalPosition);
      }
      NotifyWindowMinimize();
      break;
    case SIZE_RESTORED:
      if (last_window_state_ == ui::SHOW_STATE_NORMAL) {
        
        last_normal_bounds_ = GetBounds();
        last_normal_bounds_before_move_ = last_normal_bounds_;
      } else {
        switch (last_window_state_) {
          case ui::SHOW_STATE_MAXIMIZED:
            last_window_state_ = ui::SHOW_STATE_NORMAL;
            root_view_->SetInsets(gfx::Insets(0));
            NotifyWindowUnmaximize();
            break;
          case ui::SHOW_STATE_MINIMIZED:
            if (IsFullscreen()) {
              last_window_state_ = ui::SHOW_STATE_FULLSCREEN;
              NotifyWindowEnterFullScreen();
            } else {
              last_window_state_ = ui::SHOW_STATE_NORMAL;
              
              
              if (has_frame()) {
                SetBounds(last_normal_bounds_, false);
              }
              NotifyWindowRestore();
            }