### 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](https://www.github.com/electron/electron/issues) for a feature request that matches the one I want to file, without success.

### Electron Version

12.0.5

### What operating system are you using?

macOS

### Operating System Version

11.2.3

### What arch are you using?

arm64 (including Apple Silicon)

### Last Known Working Electron version

_No response_

### Expected Behavior

`document.hasFocus()` is only `true` for the window that has focus.

### Actual Behavior

Ever window reports `document.hasFocus()` to be `true` right after opening.

### Testcase Gist URL

https://gist.github.com/16e6fc829febd0cab115dfd0850a31be

### Additional Information

_No response_
shell/browser/api/electron_api_web_contents.cc
params.post_data = body;
    params.load_type = content::NavigationController::LOAD_TYPE_HTTP_POST;
  }
  GURL base_url_for_data_url;
  if (options.Get("baseURLForDataURL", &base_url_for_data_url)) {
    params.base_url_for_data_url = base_url_for_data_url;
    params.load_type = content::NavigationController::LOAD_TYPE_DATA;
  }
  bool reload_ignoring_cache = false;
  if (options.Get("reloadIgnoringCache", &reload_ignoring_cache) &&
      reload_ignoring_cache) {
    params.reload_type = content::ReloadType::BYPASSING_CACHE;
  }
   Calling LoadURLWithParams() can trigger JS which destroys |this|.
  auto weak_this = GetWeakPtr();
  params.transition_type = ui::PAGE_TRANSITION_TYPED;
  params.override_user_agent = content::NavigationController::UA_OVERRIDE_TRUE;
   Discord non-committed entries to ensure that we don't re-use a pending
   entry
  ontents()->GetController().DiscardNonCommittedEntries();
  ontents()->GetController().LoadURLWithParams(params);
   ⚠️WARNING!⚠️
   LoadURLWithParams() triggers JS events which can call destroy() on |this|.
   It's not safe to assume that |this| points to valid memory at this point.
  if (!weak_this || !ontents())
    return;
   Required to make beforeunload handler work.
  NotifyUserActivation();
}
 TODO(MarshallOfSound): Figure out what we need to do with post data here, I