### 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 (!::IsWindow(taskbar)) {
    APPBARDATA taskbar_data = {sizeof(APPBARDATA), 0, 0, 0};
    unsigned int taskbar_state = SHAppBarMessage(ABM_GETSTATE, &taskbar_data);
    if (!(taskbar_state & ABS_AUTOHIDE))
      return false;
    taskbar_data.hWnd = ::FindWindow(L"Shell_TrayWnd", NULL);
    if (!::IsWindow(taskbar_data.hWnd))
      return false;
    SHAppBarMessage(ABM_GETTASKBARPOS, &taskbar_data);
    if (taskbar_data.uEdge == edge)
      taskbar = taskbar_data.hWnd;
  }