* **Electron Version** (output of `node_modules/.bin/electron --version`):
  * 5.0.0-beta.2
* **Operating System** (Platform and Version):
  * Windows 7 Professional (SP1)

### Expected Behavior
Not crash

### Actual behavior
Crash 3221225477

### To Reproduce
https://github.com/Gvozd/electron-quick-start/tree/issue-16883
based on electron-quick-start. only updated electron to 5.0.0-beta.2
try to open devtools from menu - crash

atom/browser/ui/views/menu_bar.cc
aura::Window* window = initial_focus->GetWidget()->GetNativeWindow();
    if (!window || !window->GetRootWindow())
      return false;
  }
  bool result = views::AccessiblePaneView::SetPaneFocus(initial_focus);
  if (result) {
    auto children = GetChildrenInZOrder();
    std::set<ui::KeyboardCode> reg;
    for (int i = 0, n = children.size(); i < n; ++i) {
      auto* button = static_cast<SubmenuButton*>(children[i]);
      bool shifted = false;
      auto keycode =
          atom::KeyboardCodeFromCharCode(button->accelerator(), &shifted);
      
      
      if (keycode != ui::VKEY_UNKNOWN && reg.find(keycode) != reg.end()) {
        reg.insert(keycode);
        focus_manager()->RegisterAccelerator(
            ui::Accelerator(keycode, ui::EF_NONE),
            ui::AcceleratorManager::kNormalPriority, this);
      }
    }
    
    focus_manager()->RegisterAccelerator(
        ui::Accelerator(ui::VKEY_MENU, ui::EF_ALT_DOWN),
        ui::AcceleratorManager::kNormalPriority, this);
  }
  return result;
}
void MenuBar::RemovePaneFocus() {