### Preflight Checklist

- [X] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
- [X] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/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

14.0.0-beta.12

### What operating system are you using?

Windows

### Operating System Version

10.0.19042 Build 19042

### What arch are you using?

x64

### Last Known Working Electron version

13

### Expected Behavior

Window should be transparent

### Actual Behavior

Open a window with transparency enabled and delete the dom, the window will be white instead of transparent.
**Also seems like settings the backgroundColor property has no longer an effect.** I always see a white window

```
const {app, BrowserWindow} = require('electron')
const path = require("path");

function createWindow () {
	const mainWindow = new BrowserWindow({
		transparent: true,
		frame: false,
	})

	mainWindow.loadURL('https://example.com')
	mainWindow.webContents.openDevTools()
}

app.whenReady().then(createWindow)
```

### Testcase Gist URL

https://gist.github.com/e124340107f6c4a3ade8b36d98a16b9a

### Additional Information

_No response_
shell/browser/api/electron_api_web_contents.cc
#include "components/printing/browser/print_manager_utils.h"
#include "printing/backend/print_backend.h"  
#include "printing/mojom/print.mojom.h"
#include "shell/browser/printing/print_preview_message_handler.h"
#include "shell/browser/printing/print_view_manager_electron.h"
#if defined(OS_WIN)
#include "printing/backend/win_helper.h"
#endif
#endif
#if BUILDFLAG(ENABLE_COLOR_CHOOSER)
#include "chrome/browser/ui/color_chooser.h"
#endif
#if BUILDFLAG(ENABLE_PICTURE_IN_PICTURE)
#include "chrome/browser/picture_in_picture/picture_in_picture_window_manager.h"
#endif
#if BUILDFLAG(ENABLE_PDF_VIEWER)
#include "components/pdf/browser/pdf_ontents_helper.h"  
#include "shell/browser/electron_pdf_ontents_helper_client.h"
#endif
#if BUILDFLAG(ENABLE_PLUGINS)
#include "content/public/browser/plugin_service.h"
#endif
#ifndef MAS_BUILD
#include "chrome/browser/hang_monitor/hang_crash_dump.h"  
#endif
namespace gin {
#if BUILDFLAG(ENABLE_PRINTING)
template <>
struct Converter<printing::mojom::MarginType> {
  static bool FromV8(v8::Isolate* isolate,