### 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](https://www.github.com/electron/electron/issues) for a feature request that matches the one I want to file, without success.

### Electron Version

12.0.0

### What operating system are you using?

macOS

### Operating System Version

10.14.0

### What arch are you using?

x64

### Last Known Working Electron version

---

### Expected Behavior

No crash when calling method

### Actual Behavior

App crashes when calling `getBackgroundColr()`

### Testcase Gist URL

https://gist.github.com/d50e366f070104cac377fd7a48722cbe

### Additional Information

_No response_


shell/browser/native_window_views.cc
wm::SetShadowElevation(GetNativeWindow(),
                         has_shadow ? wm::kShadowElevationInactiveWindow
                                    : wm::kShadowElevationNone);
}
bool NativeWindowViews::HasShadow() {
  return GetNativeWindow()->GetProperty(wm::kShadowElevationKey) !=
         wm::kShadowElevationNone;
}
void NativeWindowViews::SetOpacity(const double opacity) {
#if defined(OS_WIN)
  const double boundedOpacity = base::ClampToRange(opacity, 0.0, 1.0);
  HWND hwnd = GetAcceleratedWidget();
  if (!layered_) {
    LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
    ex_style |= WS_EX_LAYERED;
    ::SetWindowLong(hwnd, GWL_EXSTYLE, ex_style);
    layered_ = true;
  }
  ::SetLayeredWindowAttributes(hwnd, 0, boundedOpacity * 255, LWA_ALPHA);
  opacity_ = boundedOpacity;
#else
  opacity_ = 1.0;  
#endif
}
double NativeWindowViews::GetOpacity() {
  return opacity_;
}
void NativeWindowViews::SetIgnoreMouseEvents(bool ignore, bool forward) {