### 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 for an issue that matches the one I want to file, without success.

### Issue Details

* **Electron Version:** 6.0.0-beta.13
* **Operating System:** Windows 12

### Expected Behavior

The documentation for the App events `browser-window-created` and `web-contents-created` state that the first parameter is an `Event`. I therefore expect the first parameter to be an `Event`.

### Actual Behavior

The first parameter for both of these events is `undefined`. (The second parameter is a `BrowserWindow` and `WebContents`, respectively, as documented.)
shell/browser/api/event_emitter.h
private:
  
  template <typename... Args>
  bool EmitWithEvent(base::StringPiece name,
                     v8::Local<v8::Object> event,
                     Args&&... args) {
    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
    v8::Locker locker(isolate());
    v8::HandleScope handle_scope(isolate());
    EmitEvent(isolate(), GetWrapper(), name, event,
              std::forward<Args>(args)...);
    auto context = isolate()->GetCurrentContext();
    v8::Local<v8::Value> defaultPrevented;
    if (event->Get(context, StringToV8(isolate(), "defaultPrevented"))
            .ToLocal(&defaultPrevented)) {
      return defaultPrevented->BooleanValue(isolate());
    }
    return false;
  }
  DISALLOW_COPY_AND_ASSIGN(EventEmitter);
};
}  
#endif