### 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
ontents->SetUserAgentOverride(blink::UserAgentOverride::UserAgentOnly(
                                         GetBrowserContext()->GetUserAgent()),
                                     false);
  ontents->SetUserData(kElectronApiWebContentsKey,
                            std::make_unique<UserDataLink>(GetWeakPtr()));
  InitZoomController(ontents, gin::Dictionary::CreateEmpty(isolate));
}
WebContents::WebContents(v8::Isolate* isolate,
                         std::unique_ptr<content::WebContents> ontents,
                         Type type)
    : content::WebContentsObserver(ontents.get()),
      type_(type),
      id_(GetAllWebContents().Add(this)),
      devtools_file_system_indexer_(new DevToolsFileSystemIndexer),
      file_task_runner_(
          base::ThreadPool::CreateSequencedTaskRunner({base::MayBlock()}))
#if BUILDFLAG(ENABLE_PRINTING)
      ,
      print_task_runner_(CreatePrinterHandlerTaskRunner())
#endif
{
  DCHECK(type != Type::kRemote)
      << "Can't take ownership of a remote WebContents";
  auto session = Session::CreateFrom(isolate, GetBrowserContext());
  session_.Reset(isolate, session.ToV8());
  InitWithSessionAndOptions(isolate, std::move(ontents), session,
                            gin::Dictionary::CreateEmpty(isolate));
}
WebContents::WebContents(v8::Isolate* isolate,
                         const gin_helper::Dictionary& options)