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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.h
class QuotaPermissionContext;
}  
namespace net {
class SSLCertRequestInfo;
}
namespace electron {
class NotificationPresenter;
class PlatformNotificationService;
class ElectronBrowserClient : public content::ContentBrowserClient,
                              public content::RenderProcessHostObserver {
 public:
  static ElectronBrowserClient* Get();
  static void SetApplicationLocale(const std::string& locale);
  ElectronBrowserClient();
  ~ElectronBrowserClient() override;
  using Delegate = content::ContentBrowserClient;
  void set_delegate(Delegate* delegate) { delegate_ = delegate; }
  
  content::WebContents* GetWebContentsFromProcessID(int process_id);
  
  static void SuppressRendererProcessRestartForOnce();
  NotificationPresenter* GetNotificationPresenter();
  void WebNotificationAllowed(int render_process_id,
                              base::OnceCallback<void(bool, bool)> callback);
  
  std::vector<std::unique_ptr<content::NavigationThrottle>>
  CreateThrottlesForNavigation(content::NavigationHandle* handle) override;