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
InspectableWebContents* inspectable_web_contents)
    : NativeBrowserView(inspectable_web_contents) {}
NativeBrowserViewViews::~NativeBrowserViewViews() = default;
void NativeBrowserViewViews::SetAutoResizeFlags(uint8_t flags) {
  auto_resize_flags_ = flags;
  ResetAutoResizeProportions();
}
void NativeBrowserViewViews::UpdateDraggableRegions(
    const std::vector<mojom::DraggableRegionPtr>& regions) {
  
  
  
  
  
  
  
  auto const offset = GetBounds().OffsetFromOrigin();
  auto snapped_regions = mojo::Clone(regions);
  for (auto& snapped_region : snapped_regions) {
    snapped_region->bounds.Offset(offset);
    snapped_region->draggable = true;
  }
  draggable_region_ = DraggableRegionsToSkRegion(snapped_regions);
}
void NativeBrowserViewViews::SetAutoResizeProportions(