### 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
TRACE_EVENT1("electron", "WebContents::MessageHost", "channel", channel);
   webContents.emit('ipc-message-host', new Event(), channel, args);
  EmitWithSender("ipc-message-host", render_frame_host,
                 electron::mojom::ElectronBrowser::InvokeCallback(), channel,
                 std::move(arguments));
}
void WebContents::UpdateDraggableRegions(
    std::vector<mojom::DraggableRegionPtr> regions) {
  for (ExtendedWebContentsObserver& observer : observers_)
    observer.OnDraggableRegionsUpdated(regions);
}
void WebContents::DidStartNavigation(
    content::NavigationHandle* navigation_handle) {
  EmitNavigationEvent("did-start-navigation", navigation_handle);
}
void WebContents::DidRedirectNavigation(
    content::NavigationHandle* navigation_handle) {
  EmitNavigationEvent("did-redirect-navigation", navigation_handle);
}
void WebContents::ReadyToCommitNavigation(
    content::NavigationHandle* navigation_handle) {
   Don't focus content in an inactive window.
  if (!owner_window())
    return;
#if defined(OS_MAC)
  if (!owner_window()->IsActive())
    return;
#else
  if (!owner_window()->widget()->IsActive())
    return;