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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
return "Chrome/" CHROME_VERSION_STRING;
}
std::string ElectronBrowserClient::GetUserAgent() {
  if (user_agent_override_.empty())
    return GetApplicationUserAgent();
  return user_agent_override_;
}
void ElectronBrowserClient::SetUserAgent(const std::string& user_agent) {
  user_agent_override_ = user_agent;
}
void ElectronBrowserClient::RegisterNonNetworkNavigationURLLoaderFactories(
    int frame_tree_node_id,
    NonNetworkURLLoaderFactoryMap* factories) {
  content::WebContents* web_contents =
      content::WebContents::FromFrameTreeNodeId(frame_tree_node_id);
  api::Protocol* protocol = api::Protocol::FromWrappedClass(
      v8::Isolate::GetCurrent(), web_contents->GetBrowserContext());
#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
  factories->emplace(
      extensions::kExtensionScheme,
      extensions::CreateExtensionNavigationURLLoaderFactory(
          web_contents->GetBrowserContext(),
          false ));
#endif
  if (protocol)
    protocol->RegisterURLLoaderFactories(factories);
}
#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
namespace {
class FileURLLoaderFactory : public network::mojom::URLLoaderFactory {