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Ref #19447

### Issue Details

* **Electron Version:**
  * 9.0.0-beta.24
* **Operating System:**
  * macOS 10.15, Windows 10
* **Last Known Working Electron version:**
  * none

### Expected Behavior
`e.sender` object received from an extension background page should have `webPreferences` and `session` initialized. It looks like `options` in `api::WebContents` constructor don't get initialized properly for an extension background page.

### Actual Behavior
`e.sender` object doesn't have `session` and `e.sender.getWebPreferences()` returns `null`.

### To Reproduce
https://github.com/sentialx/electron-quick-start/tree/extensions/no-session

Just run it and you will see something like this:
![image](https://user-images.githubusercontent.com/11065386/82097607-82994400-9703-11ea-8291-0eb987d8aca0.png)

### Additional Information
This is a real blocker for anyone who would want to provide own `chrome` APIs in background pages initialized from different sessions.
shell/browser/api/electron_api_web_contents.cc
base::BindRepeating(&Ws::OnPaint, base::Unretained(this)));
      params.view = view;
      params.delegate_view = view;
      ontents = content::Ws::Create(params);
      view->SetWs(ontents.get());
    } else {
#endif
      ontents = content::Ws::Create(params);
#if BUILDFLAG(ENABLE_OSR)
    }
  } else if (IsOffScreen()) {
    bool transparent = false;
    options.Get("transparent", &transparent);
    content::Ws::CreateParams params(session->browser_context());
    auto* view = new OffScreenWsView(
        transparent,
        base::BindRepeating(&Ws::OnPaint, base::Unretained(this)));
    params.view = view;
    params.delegate_view = view;
    ontents = content::Ws::Create(params);
    view->SetWs(ontents.get());
#endif
  } else {
    content::Ws::CreateParams params(session->browser_context());
    params.initially_hidden = !initially_shown;
    ontents = content::Ws::Create(params);
  }
  InitWithSessionAndOptions(isolate, std::move(ontents), session, options);
}
void Ws::InitZoomController(content::Ws* ontents,