Since #19488, the network service is enabled and the old path has been deleted. Some features are broken as a result and will need to be fixed before 8.0.0. This is a tracking issue for those features.

- [x] webRequest API (zcbenz)
- [x] service workers on file protocol (#20132)
- [x] session.clearAuthCache - tests (#20015)
- [x] session.getBlobData (#20041)
- [x] session.setUserAgent (#20014)
- [x] custom standard schemes / registerSchemesAsPrivileged
- [x] Rewire Login Handler from NetworkDelegate into ProxyingURLLoaderFactory
- [x] fix 'login' event not firing on net requests

cc @deepak1556 @jkleinsc @zcbenz 
shell/browser/api/atom_api_session.cc
proxy_config::prefs::kProxy,
        std::make_unique<base::Value>(ProxyConfigDictionary::CreateFixedServers(
            proxy_rules, bypass_list)),
        WriteablePrefStore::DEFAULT_PREF_WRITE_FLAGS);
  }
  base::ThreadTaskRunnerHandle::Get()->PostTask(
      FROM_HERE, base::BindOnce(util::Promise<void*>::ResolveEmptyPromise,
                                std::move(promise)));
  return handle;
}
void Session::SetDownloadPath(const base::FilePath& path) {
  browser_context_->prefs()->SetFilePath(prefs::kDownloadDefaultDirectory,
                                         path);
}
void Session::EnableNetworkEmulation(const mate::Dictionary& options) {
  auto conditions = network::mojom::NetworkConditions::New();
  options.Get("offline", &conditions->offline);
  options.Get("downloadThroughput", &conditions->download_throughput);
  options.Get("uploadThroughput", &conditions->upload_throughput);
  double latency = 0.0;
  if (options.Get("latency", &latency) && latency) {
    conditions->latency = base::TimeDelta::FromMillisecondsD(latency);
  }
  auto* network_context = content::BrowserContext::GetDefaultStoragePartition(
                              browser_context_.get())
                              ->GetNetworkContext();
  network_context->SetNetworkConditions(network_emulation_token_,
                                        std::move(conditions));
}
void Session::DisableNetworkEmulation() {