### 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

12.0.1

### What operating system are you using?

Windows

### Operating System Version

Windows 10 Pro 2020

### What arch are you using?

x64

### Last Known Working Electron version

11.3.0

### Expected Behavior

The app works perfectly fine with an embedded video player.

### Actual Behavior

The app crashes when creating an element with an embedded video player.

### Testcase Gist URL

https://github.com/pavladan/mpv.js-on-react

Change the version of electron to 12.0.1 to see the crash, 11.3.0 works perfectly fine.

Note: In order to see the crash on 12.0.1, adjustments to the settings must be made
```
const win = new BrowserWindow({
    width: 1280,
    height: 574,
    autoHideMenuBar: true,
    useContentSize: process.platform !== "linux",
    title: "mpv.js example player",
    webPreferences: {
      nodeIntegration: true,
      plugins: true,
      enableRemoteModule: true,
      nodeIntegrationInSubFrames: true,
      contextIsolation: false,
      worldSafeExecuteJavaScript: false
    },
  });
```

shell/renderer/renderer_client_base.cc
return new ElectronExtensionsClient;
}
#endif
bool RendererClientBase::IsWebViewFrame(
    v8::Handle<v8::Context> context,
    content::RenderFrame* render_frame) const {
  auto* isolate = context->GetIsolate();
  if (render_frame->IsMainFrame())
    return false;
  gin::Dictionary window_dict(
      isolate, GetContext(render_frame->GetWebFrame(), isolate)->Global());
  v8::Local<v8::Object> frame_element;
  if (!window_dict.Get("frameElement", &frame_element))
    return false;
  gin_helper::Dictionary frame_element_dict(isolate, frame_element);
  v8::Local<v8::Object> internal;
  if (!frame_element_dict.GetHidden("internal", &internal))
    return false;
  return !internal.IsEmpty();
}
}