* [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:**
  * 7.0.0-beta.7
* **Operating System:**
  * Windows 10
* **Last Known Working Electron version:**
  * 6

### Expected Behavior
Cookies are received

### Actual Behavior
response.headers["set-cookie"] never contains cookies

### To Reproduce
Do a request using the net module as described here: https://electronjs.org/docs/api/net
to any site that will return cookies.

shell/browser/api/atom_api_url_loader.cc
MojoResult result) {
    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
    is_writing_ = false;
    if (result == MOJO_RESULT_OK) {
      promise.Resolve();
    } else {
      promise.RejectWithErrorMessage("mojo result not ok");
      Finished();
    }
  }
  
  
  void Done() {
    if (size_callback_) {
      std::move(size_callback_).Run(net::OK, bytes_written_);
      Finished();
    }
  }
  void Finished() {
    size_callback_.Reset();
    body_func_.Reset();
    receiver_.reset();
    data_producer_.reset();
  }
  GetSizeCallback size_callback_;
  mojo::Receiver<network::mojom::ChunkedDataPipeGetter> receiver_{this};
  std::unique_ptr<mojo::DataPipeProducer> data_producer_;
  bool is_writing_ = false;
  uint64_t bytes_written_ = 0;
  v8::Isolate* isolate_;