GitLab

Remove code that is not used anymore with the network service enabled,
second iteration.

In particular updates/removes:
- android_protocol_handler
- aw_url_request_context_getter
- init_native_callback
- aw_safe_browsing_ui_manager
- aw_download_manager_delegate
- aw_settings

and all related call sites and usages.

Also removes code and checks which check for
features::kNetworkService being enabled/disabled.

BUG=989104

Change-Id: I9d18af050cb262ad0f07e64a3e850e5c7fb56f81
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1731929
Commit-Queue: Tim Volodine <timvolodine@chromium.org>
Reviewed-by: Richard Coles <torne@chromium.org>
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683584}