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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
PrintViewManagerBasic class does not do null check.
  if (!ontents()) {
    if (print_callback)
      std::move(print_callback).Run(false, "failed");
    return;
  }
  base::string16 printer_name =
      device_name.empty() ? default_printer : device_name;
   If there are no valid printers available on the network, we bail.
  if (printer_name.empty() || !IsDeviceNameValid(printer_name)) {
    if (print_callback)
      std::move(print_callback).Run(false, "no valid printers available");
    return;
  }
  print_settings.SetStringKey(printing::kSettingDeviceName, printer_name);
  auto* print_view_manager =
      printing::PrintViewManagerBasic::FromWs(ontents());
  auto* focused_frame = ontents()->GetFocusedFrame();
  auto* rfh = focused_frame && focused_frame->HasSelection()
                  ? focused_frame
                  : ontents()->GetMainFrame();
  print_view_manager->PrintNow(rfh, silent, std::move(print_settings),
                               std::move(print_callback));
}
void Ws::Print(gin_helper::Arguments* args) {
  gin_helper::Dictionary options =
      gin::Dictionary::CreateEmpty(args->isolate());
  base::Value settings(base::Value::Type::DICTIONARY);
  if (args->Length() >= 1 && !args->GetNext(&options)) {
    args->ThrowError("ws.print(): Invalid print settings specified.");