### 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

17.0.0

### What operating system are you using?

Windows

### Operating System Version

Windows 10 Version 21H1

### What arch are you using?

x64

### Last Known Working Electron version

14.2.3

### Expected Behavior

background should transparent if background is #00000000

### Actual Behavior

has a white background

### Testcase Gist URL

_No response_

### Additional Information

_No response_
shell/browser/api/electron_api_web_contents.cc
#endif
   Don't focus content after subframe navigations.
  if (!navigation_handle->IsInMainFrame())
    return;
   Only focus for top-level contents.
  if (type_ != Type::kBrowserWindow)
    return;
  ontents()->SetInitialFocus();
}
void WebContents::DidFinishNavigation(
    content::NavigationHandle* navigation_handle) {
  if (owner_window_) {
    owner_window_->NotifyLayoutWindowControlsOverlay();
  }
  if (!navigation_handle->HasCommitted())
    return;
  bool is_main_frame = navigation_handle->IsInMainFrame();
  content::RenderFrameHost* frame_host =
      navigation_handle->GetRenderFrameHost();
  int frame_process_id = -1, frame_routing_id = -1;
  if (frame_host) {
    frame_process_id = frame_host->GetProcess()->GetID();
    frame_routing_id = frame_host->GetRoutingID();
  }
  if (!navigation_handle->IsErrorPage()) {
     FIXME: All the Emit() calls below could potentially result in |this|
     being destroyed (by JS listening for the event and calling
     webContents.destroy()).
    auto url = navigation_handle->GetURL();
    bool is_same_document = navigation_handle->IsSameDocument();