

### 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:**
  * Tested with 8.0.0 and v9.0.0-beta.1
* **Operating System:**
  * macOS 10.15.3 (19D76)
* **Last Known Working Electron version:**
  * 7.1.12

### Expected Behavior

`navigator.mediaDevices.enumerateDevices()` should return a list of MediaDevices with a `label` and a `deviceId` property. The `deviceId` property should stay the same across reloads and restarts.

### Actual Behavior
The `deviceId` property changes with every reload/restart.

### To Reproduce
Simply execute `navigator.mediaDevices.enumerateDevices()` in the renderer process and compare the ids of the media devices to a different execution.

See this fork for an example:
https://github.com/codedrift/electron-quick-start

```sh
$ git clone https://github.com/codedrift/electron-quick-start -b media-device-ids
$ npm install
$ npm start || electron .
```

### Additional Information
It seems to work fine in a regular Chrome 80 browser. 

shell/browser/electron_browser_client.cc
if (allowed) {
    platform_util::OpenExternal(
        escaped_url, platform_util::OpenExternalOptions(), base::DoNothing());
  }
}
void HandleExternalProtocolInUI(
    const GURL& url,
    content::WebContents::OnceGetter web_contents_getter,
    bool has_user_gesture) {
  content::WebContents* web_contents = std::move(web_contents_getter).Run();
  if (!web_contents)
    return;
  auto* permission_helper =
      WebContentsPermissionHelper::FromWebContents(web_contents);
  if (!permission_helper)
    return;
  GURL escaped_url(net::EscapeExternalHandlerValue(url.spec()));
  auto callback = base::BindOnce(&OnOpenExternal, escaped_url);
  permission_helper->RequestOpenExternalPermission(std::move(callback),
                                                   has_user_gesture, url);
}
bool ElectronBrowserClient::HandleExternalProtocol(