

### Preflight Checklist
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* [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
registry->enabled_extensions().GetExtensionOrAppByURL(
          site_instance->GetSiteURL());
  if (!extension)
    return;
  extensions::ProcessMap::Get(browser_context)
      ->Remove(extension->id(), site_instance->GetProcess()->GetID(),
               site_instance->GetId());
  base::PostTask(
      FROM_HERE, {BrowserThread::IO},
      base::BindOnce(&extensions::InfoMap::UnregisterExtensionProcess,
                     browser_context->extension_system()->info_map(),
                     extension->id(), site_instance->GetProcess()->GetID(),
                     site_instance->GetId()));
#endif
}
std::unique_ptr<net::ClientCertStore>
ElectronBrowserClient::CreateClientCertStore(
    content::BrowserContext* browser_context) {
#if defined(USE_NSS_CERTS)
  return std::make_unique<net::ClientCertStoreNSS>(
      net::ClientCertStoreNSS::PasswordDelegateFactory());
#elif defined(OS_WIN)
  return std::make_unique<net::ClientCertStoreWin>();
#elif defined(OS_MACOSX)
  return std::make_unique<net::ClientCertStoreMac>();
#elif defined(USE_OPENSSL)
  return std::unique_ptr<net::ClientCertStore>();
#endif
}
std::unique_ptr<device::LocationProvider>