Here is how to quickly reproduce the bug: Electron fiddle: https://gist.github.com/josephernest/f3db7d319af407b2dcef04c7c1c514ee

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I have a `#topleft` red title bar containing multiple "tab" buttons that should fill all the available space *except* a `#topright` blue block.  
It is possible to move the main Electron window by click-and-dragging on `#topleft`'s red background, thanks to `-webkit-app-region: drag;`. This works.

[![enter image description here][1]][1]

**Problems**: 

1. clicks on `#topright` are ignored: `alert()` is not triggered  (same problem for child elements of this block)
2. `#topright span:hover { background-color: black; }` is ignored 
3. `#topright { -webkit-app-region: no-drag; }` is ignored: we can still move the window by click-and-dragging on `#topright` whereas it should not

However if we run the same HTML code *in a browser*, all is working correctly.

  [1]: https://i.stack.imgur.com/ZZPsJ.png
shell/browser/native_browser_view_views.cc
if ((auto_resize_flags_ & AutoResizeFlags::kAutoResizeVertical) &&
      !auto_vertical_proportion_set_) {
    auto* iwc_view = GetInspectableWebContentsView();
    if (!iwc_view)
      return;
    auto* view = iwc_view->GetView();
    auto view_bounds = view->bounds();
    auto_vertical_proportion_height_ =
        static_cast<float>(window_size.height()) /
        static_cast<float>(view_bounds.height());
    auto_vertical_proportion_top_ = static_cast<float>(window_size.height()) /
                                    static_cast<float>(view_bounds.y());
    auto_vertical_proportion_set_ = true;
  }
}
void NativeBrowserViewViews::AutoResize(const gfx::Rect& new_window,
                                        int width_delta,
                                        int height_delta) {
  auto* iwc_view = GetInspectableWebContentsView();
  if (!iwc_view)
    return;
  auto* view = iwc_view->GetView();
  const auto flags = GetAutoResizeFlags();
  if (!(flags & kAutoResizeWidth)) {
    width_delta = 0;
  }
  if (!(flags & kAutoResizeHeight)) {
    height_delta = 0;
  }
  if (height_delta || width_delta) {