

### Preflight Checklist
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### 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
content::RenderFrameHost* render_frame_host,
    service_manager::BinderMapWithContext<content::RenderFrameHost*>* map) {
  map->Add<network_hints::mojom::NetworkHintsHandler>(
      base::BindRepeating(&BindNetworkHintsHandler));
#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
  map->Add<extensions::mime_handler::MimeHandlerService>(
      base::BindRepeating(&BindMimeHandlerService));
#endif
}
std::unique_ptr<content::LoginDelegate>
ElectronBrowserClient::CreateLoginDelegate(
    const net::AuthChallengeInfo& auth_info,
    content::WebContents* web_contents,
    const content::GlobalRequestID& request_id,
    bool is_main_frame,
    const GURL& url,
    scoped_refptr<net::HttpResponseHeaders> response_headers,
    bool first_auth_attempt,
    LoginAuthRequiredCallback auth_required_callback) {
  return std::make_unique<LoginHandler>(
      auth_info, web_contents, is_main_frame, url, response_headers,
      first_auth_attempt, std::move(auth_required_callback));
}
std::vector<std::unique_ptr<blink::URLLoaderThrottle>>