### Issue Details
in frameless windows 
While setting browserview style to draggable by webkit-app-region : drag. the area won't be draggable after that
and it can not move main window 
### Electron Version:
11.0.1
### Operating System:
Windows 10 (1803)
Last Known Working Electron version:
not found
### Expected Behavior
Browser view moves the main window while I set the style of the body or one of the area to
-webkit-app-region: drag;

### Actual Behavior
nothing happen in browserview after styling -webkit-app-region: drag;

I know it is mention that in 11 version it is fixed. but it still dosn't work 

### To Reproduce
https://gist.github.com/pejmanpesyan/8540aad65e7c6980c45f23e5eaafafb9

shell/browser/native_window_views.cc
const gfx::Rect& bounds) const {
  if (!has_frame())
    return bounds;
  gfx::Rect content_bounds(bounds);
#if defined(OS_WIN)
  HWND hwnd = GetAcceleratedWidget();
  content_bounds.set_size(DIPToScreenRect(hwnd, content_bounds).size());
  RECT rect;
  SetRectEmpty(&rect);
  DWORD style = ::GetWindowLong(hwnd, GWL_STYLE);
  DWORD ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
  AdjustWindowRectEx(&rect, style, FALSE, ex_style);
  content_bounds.set_width(content_bounds.width() - (rect.right - rect.left));
  content_bounds.set_height(content_bounds.height() - (rect.bottom - rect.top));
  content_bounds.set_size(ScreenToDIPRect(hwnd, content_bounds).size());
#endif
  if (root_view_->HasMenu() && root_view_->IsMenuBarVisible()) {
    int menu_bar_height = root_view_->GetMenuBarHeight();
    content_bounds.set_y(content_bounds.y() + menu_bar_height);
    content_bounds.set_height(content_bounds.height() - menu_bar_height);
  }
  return content_bounds;
}
void NativeWindowViews::UpdateDraggableRegions(