### 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
}
  for (ExtendedWebContentsObserver& observer : observers_)
    observer.OnPageTitleUpdated(final_title, explicit_set);
  Emit("page-title-updated", final_title, explicit_set);
}
void WebContents::DidUpdateFaviconURL(
    content::RenderFrameHost* render_frame_host,
    const std::vector<blink::mojom::FaviconURLPtr>& urls) {
  std::set<GURL> unique_urls;
  for (const auto& iter : urls) {
    if (iter->icon_type != blink::mojom::FaviconIconType::kFavicon)
      continue;
    const GURL& url = iter->icon_url;
    if (url.is_valid())
      unique_urls.insert(url);
  }
  Emit("page-favicon-updated", unique_urls);
}
void WebContents::DevToolsReloadPage() {
  Emit("devtools-reload-page");
}
void WebContents::DevToolsFocused() {
  Emit("devtools-focused");
}
void WebContents::DevToolsOpened() {
  v8::Isolate* isolate = JavascriptEnvironment::GetIsolate();
  v8::Locker locker(isolate);
  v8::HandleScope handle_scope(isolate);
  DCHECK(inspectable_ontents_);
  DCHECK(inspectable_ontents_->GetDevToolsWebContents());