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
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/task/post_task.h"
#include "chrome/browser/browser_process.h"
#include "chrome/common/pref_names.h"
#include "components/download/public/common/download_danger_type.h"
#include "components/download/public/common/download_url_parameters.h"
#include "components/prefs/pref_service.h"
#include "components/prefs/value_map_pref_store.h"
#include "components/proxy_config/proxy_config_dictionary.h"
#include "components/proxy_config/proxy_config_pref_names.h"
#include "content/public/browser/browser_task_traits.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/download_item_utils.h"
#include "content/public/browser/download_manager_delegate.h"
#include "content/public/browser/network_service_instance.h"
#include "content/public/browser/storage_partition.h"
#include "mojo/public/cpp/bindings/strong_binding.h"
#include "native_mate/dictionary.h"
#include "native_mate/object_template_builder.h"
#include "net/base/completion_repeating_callback.h"
#include "net/base/load_flags.h"
#include "net/http/http_auth_handler_factory.h"
#include "net/http/http_auth_preferences.h"
#include "net/http/http_cache.h"
#include "services/network/network_service.h"
#include "services/network/public/cpp/features.h"
#include "shell/browser/api/atom_api_cookies.h"
#include "shell/browser/api/atom_api_download_item.h"
#include "shell/browser/api/atom_api_net_log.h"