### Preflight Checklist
<!-- Please ensure you've completed the following steps by replacing [ ] with [x]-->

* [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:**
  * 8.0.0
* **Operating System:**
  * Windows 10 Pro (1709)

### Expected Behavior
Using Notification API in main process with `timeoutType: 'never` I expected that the notification disappears only when the user clicks on it.  

### Actual Behavior
After few seconds the notification disappers.

### To Reproduce

```
  const newNotification = new Notification({title: 'I am a main process Notification!', timeoutType: 'never'})
  newNotification.show()
```

```sh
$ git clone https://github.com/p-fusi/electron-quick-start -b master
$ npm install
$ npm run start
```


shell/browser/notifications/win/windows_toast_notification.cc
IXmlDocument* doc,
                                                  IXmlNodeList** node_list,
                                                  uint32_t req_length) {
  tag->Reset(L"text");
  if (!tag->success())
    return E_FAIL;
  RETURN_IF_FAILED(doc->GetElementsByTagName(*tag, node_list));
  uint32_t node_length;
  RETURN_IF_FAILED((*node_list)->get_Length(&node_length));
  return node_length >= req_length;
}
HRESULT WindowsToastNotification::AppendTextToXml(IXmlDocument* doc,
                                                  IXmlNode* node,
                                                  const std::wstring& text) {
  ScopedHString str(text);
  if (!str.success())
    return E_FAIL;
  ComPtr<IXmlText> xml_text;
  RETURN_IF_FAILED(doc->CreateTextNode(str, &xml_text));
  ComPtr<IXmlNode> text_node;
  RETURN_IF_FAILED(xml_text.As(&text_node));
  ComPtr<IXmlNode> append_node;
  RETURN_IF_FAILED(node->AppendChild(text_node.Get(), &append_node));
  return S_OK;
}
HRESULT WindowsToastNotification::XmlDocumentFromString(