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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
promise.RejectWithErrorMessage("takeHeapSnapshot failed");
    return handle;
  }
  auto* frame_host = ontents()->GetMainFrame();
  if (!frame_host) {
    promise.RejectWithErrorMessage("takeHeapSnapshot failed");
    return handle;
  }
   This dance with `base::Owned` is to ensure that the interface stays alive
   until the callback is called. Otherwise it would be closed at the end of
   this function.
  auto electron_renderer =
      std::make_unique<mojo::AssociatedRemote<mojom::ElectronRenderer>>();
  frame_host->GetRemoteAssociatedInterfaces()->GetInterface(
      electron_renderer.get());
  auto* raw_ptr = electron_renderer.get();
  (*raw_ptr)->TakeHeapSnapshot(
      mojo::WrapPlatformFile(file.TakePlatformFile()),
      base::BindOnce(
          [](mojo::AssociatedRemote<mojom::ElectronRenderer>* ep,
             gin_helper::Promise<void> promise, bool success) {
            if (success) {
              promise.Resolve();
            } else {
              promise.RejectWithErrorMessage("takeHeapSnapshot failed");
            }
          },
          base::Owned(std::move(electron_renderer)), std::move(promise)));
  return handle;
}