### 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
if (GetNativeWindow() && GetNativeWindow()->GetHost())
    return GetNativeWindow()->GetHost()->GetAcceleratedWidget();
  else
    return gfx::kNullAcceleratedWidget;
}
NativeWindowHandle NativeWindowViews::GetNativeWindowHandle() const {
  return GetAcceleratedWidget();
}
gfx::Rect NativeWindowViews::ContentBoundsToWindowBounds(
    const gfx::Rect& bounds) const {
  if (!has_frame())
    return bounds;
  gfx::Rect window_bounds(bounds);
#if defined(OS_WIN)
  if (widget()->non_client_view()) {
    HWND hwnd = GetAcceleratedWidget();
    gfx::Rect dpi_bounds = DIPToScreenRect(hwnd, bounds);
    window_bounds = ScreenToDIPRect(
        hwnd, widget()->non_client_view()->GetWindowBoundsForClientBounds(
                  dpi_bounds));
  }
#endif
  if (root_view_->HasMenu() && root_view_->IsMenuBarVisible()) {
    int menu_bar_height = root_view_->GetMenuBarHeight();
    window_bounds.set_y(window_bounds.y() - menu_bar_height);
    window_bounds.set_height(window_bounds.height() + menu_bar_height);
  }
  return window_bounds;
}
gfx::Rect NativeWindowViews::WindowBoundsToContentBounds(