### 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 feature request that matches the one I want to file, without success.

### Electron Version

14.0.1

### What operating system are you using?

macOS

### Operating System Version

macOS Big Sur 11.6.1

### What arch are you using?

x64

### Last Known Working Electron version

14.0.0

### Expected Behavior


When `BrowserView.setBackgroundColor` is called with an explicit color, expect the background to be the color selected.

When `BrowserView.setBackgroundColor` is not called, expect the background of the `BrowserView` to be transparent by default; and can see through `BrowserWindow`'s background color.



### Actual Behavior

The `BrowserView` background is always white.

### Testcase Gist URL

https://gist.github.com/kevinlinv/2de60478ffec6a2f18f1ec0fc6f5add9

### Additional Information

Here is a quick recording that reproduces the error.

https://user-images.githubusercontent.com/44967897/140694174-e27aff28-1847-4813-bc46-d9fda6569128.mp4


shell/browser/api/electron_api_web_contents.cc
if (print_callback)
      std::move(print_callback).Run(false, info.first);
    return;
  }
   If the user has passed a deviceName use it, otherwise use default printer.
  std::u16string printer_name = device_name.empty() ? info.second : device_name;
   If there are no valid printers available on the network, we bail.
  if (printer_name.empty() || !IsDeviceNameValid(printer_name)) {
    if (print_callback)
      std::move(print_callback).Run(false, "no valid printers available");
    return;
  }
  print_settings.SetStringKey(printing::kSettingDeviceName, printer_name);
  auto* print_view_manager =
      PrintViewManagerElectron::FromWebContents(ontents());
  if (!print_view_manager)
    return;
  auto* focused_frame = ontents()->GetFocusedFrame();
  auto* rfh = focused_frame && focused_frame->HasSelection()
                  ? focused_frame
                  : ontents()->GetMainFrame();
  print_view_manager->PrintNow(rfh, silent, std::move(print_settings),
                               std::move(print_callback));
}
void WebContents::Print(gin::Arguments* args) {
  gin_helper::Dictionary options =
      gin::Dictionary::CreateEmpty(args->isolate());
  base::Value settings(base::Value::Type::DICTIONARY);
  if (args->Length() >= 1 && !args->GetNext(&options)) {
    gin_helper::ErrorThrower(args->isolate())