### Preflight Checklist

- [X] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/main/CONTRIBUTING.md) for this project.
- [X] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/main/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 bug report that matches the one I want to file, without success.

### Electron Version

16.0.0

### What operating system are you using?

Windows

### Operating System Version

WIN10 20H2

### What arch are you using?

x64

### Last Known Working Electron version

_No response_

### Expected Behavior

 win.webContents.savePage('d:/aaaaaa.html', 'HTMLComplete').then(() => {
      console.log('Page was saved successfully.')
    }).catch(err => {
      console.log(err)
    })

it will generate a html page file at d: 

### Actual Behavior

savePage has three formats that can be used

if use HTMLComplete
 only produced a aaaaaa_files empty folder

if use HTMLonly 
No files are generated nor error callbacks are generated

MHTML option works fine

### Testcase Gist URL

_No response_

### Additional Information

_No response_
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::kWebView;
}
void WebContents::AttachToIframe(content::WebContents* embedder_ontents,
                                 int embedder_frame_id) {
  attached_ = true;
  if (guest_delegate_)
    guest_delegate_->AttachToIframe(embedder_ontents, embedder_frame_id);
}
bool WebContents::IsOffScreen() const {
#if BUILDFLAG(ENABLE_OSR)
  return type_ == Type::kOffScreen;
#else
  return false;
#endif
}
#if BUILDFLAG(ENABLE_OSR)
void WebContents::OnPaint(const gfx::Rect& dirty_rect, const SkBitmap& bitmap) {