### 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 for an issue that matches the one I want to file, without success.

### Issue Details

* **Electron Version:**
  * 10.1.1
* **Operating System:**
  * macOS 10.15.4

We recently started launching as hidden on macOS (that is, `show: false` or `browserWindow.hide()` while loading the page, followed by `browserWindow.show()` when the dock icon is clicked). This results in some busted focus behavior on the first activation of the window. The second activation restores it.

### Expected Behavior
The guest page receives a `focus` event on the first activation of the app, when created with `show: false`.

### Actual Behavior
The guest page doesn't receive the first `focus` event. Subsequent activations do trigger a `focus` event.

### To Reproduce
[Electron Fiddle](https://gist.github.com/CharlieHess/c507468cd40630d04f58c6514100b997)

shell/browser/api/electron_api_web_contents.cc
const ui::Cursor& cursor = webcursor.cursor();
  if (cursor.type() == ui::mojom::CursorType::kCustom) {
    Emit("cursor-changed", CursorTypeToString(cursor),
         gfx::Image::CreateFrom1xBitmap(cursor.custom_bitmap()),
         cursor.image_scale_factor(),
         gfx::Size(cursor.custom_bitmap().width(),
                   cursor.custom_bitmap().height()),
         cursor.custom_hotspot());
  } else {
    Emit("cursor-changed", CursorTypeToString(cursor));
  }
}
bool WebContents::IsGuest() const {
  return type_ == Type::WEB_VIEW;
}
void WebContents::AttachToIframe(content::WebContents* embedder_ontents,
                                 int embedder_frame_id) {
  if (guest_delegate_)
    guest_delegate_->AttachToIframe(embedder_ontents, embedder_frame_id);
}
bool WebContents::IsOffScreen() const {
#if BUILDFLAG(ENABLE_OSR)
  return type_ == Type::OFF_SCREEN;
#else
  return false;
#endif
}
#if BUILDFLAG(ENABLE_OSR)
void WebContents::OnPaint(const gfx::Rect& dirty_rect, const SkBitmap& bitmap) {