### 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
if (inspectable_ontents_)
    inspectable_ontents_->SetDevToolsWebContents(devtools->ontents());
}
v8::Local<v8::Value> WebContents::GetNativeView(v8::Isolate* isolate) const {
  gfx::NativeView ptr = ontents()->GetNativeView();
  auto buffer = node::Buffer::Copy(isolate, reinterpret_cast<char*>(&ptr),
                                   sizeof(gfx::NativeView));
  if (buffer.IsEmpty())
    return v8::Null(isolate);
  else
    return buffer.ToLocalChecked();
}
v8::Local<v8::Value> WebContents::DevToolsWebContents(v8::Isolate* isolate) {
  if (devtools_ontents_.IsEmpty())
    return v8::Null(isolate);
  else
    return v8::Local<v8::Value>::New(isolate, devtools_ontents_);
}
v8::Local<v8::Value> WebContents::Debugger(v8::Isolate* isolate) {
  if (debugger_.IsEmpty()) {
    auto handle = electron::api::Debugger::Create(isolate, ontents());
    debugger_.Reset(isolate, handle.ToV8());
  }
  return v8::Local<v8::Value>::New(isolate, debugger_);
}
content::RenderFrameHost* WebContents::MainFrame() {
  return ontents()->GetMainFrame();
}
void WebContents::NotifyUserActivation() {