### 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
content::WebContents* source,
    const content::NativeWebKeyboardEvent& event) {
  if (event.GetType() == blink::WebInputEvent::Type::kRawKeyDown ||
      event.GetType() == blink::WebInputEvent::Type::kKeyUp) {
    bool prevent_default = Emit("before-input-event", event);
    if (prevent_default) {
      return content::KeyboardEventProcessingResult::HANDLED;
    }
  }
  return content::KeyboardEventProcessingResult::NOT_HANDLED;
}
void WebContents::ContentsZoomChange(bool zoom_in) {
  Emit("zoom-changed", zoom_in ? "in" : "out");
}
void WebContents::EnterFullscreenModeForTab(
    content::RenderFrameHost* requesting_frame,
    const blink::mojom::FullscreenOptions& options) {
  auto* source = content::WebContents::FromRenderFrameHost(requesting_frame);
  auto* permission_helper =
      WebContentsPermissionHelper::FromWebContents(source);
  auto callback =
      base::BindRepeating(&WebContents::OnEnterFullscreenModeForTab,
                          base::Unretained(this), requesting_frame, options);
  permission_helper->RequestFullscreenPermission(callback);
}
void WebContents::OnEnterFullscreenModeForTab(