### 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
base::BindRepeating(&WebContents::OnPaint, base::Unretained(this)));
      params.view = view;
      params.delegate_view = view;
      ontents = content::WebContents::Create(params);
      view->SetWebContents(ontents.get());
    } else {
#endif
      ontents = content::WebContents::Create(params);
#if BUILDFLAG(ENABLE_OSR)
    }
  } else if (IsOffScreen()) {
    bool transparent = false;
    options.Get("transparent", &transparent);
    content::WebContents::CreateParams params(session->browser_context());
    auto* view = new OffScreenWebContentsView(
        transparent,
        base::BindRepeating(&WebContents::OnPaint, base::Unretained(this)));
    params.view = view;
    params.delegate_view = view;
    ontents = content::WebContents::Create(params);
    view->SetWebContents(ontents.get());
#endif
  } else {
    content::WebContents::CreateParams params(session->browser_context());
    params.initially_hidden = !initially_shown;
    ontents = content::WebContents::Create(params);
  }
  InitWithSessionAndOptions(isolate, std::move(ontents), session, options);
}
void WebContents::InitZoomController(content::WebContents* ontents,