When we make this change we should also somehow differentiate between proxies that are set by a user installed extension (which can be disabled), and proxies enforced by a policy installed extension (which can not be disabled).

When we fix this we need to address the following problem:

Currently there is no way for the UI to identify when "Allow shared proxies" is respected for shared networks with proxies applied.

Thanks for volunteering to finally deprecate this! :)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/da931601784415384334deb474cb85dc34a532d4

commit da931601784415384334deb474cb85dc34a532d4
Author: Toni Barzic <tbarzic@chromium.org>
Date: Wed Jan 09 18:20:54 2019

Remove unused parts of UIProxyConfig

Also, removes proxy_cros_settings_parser, which depends on
UIProxyConfig, but doesn't seem to be used anymore.

BUG=662529

Change-Id: I68dc34a1f2110411e27a226e1becb1ae1a490079
Reviewed-on: https://chromium-review.googlesource.com/c/1401847
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Toni Baržić <tbarzic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#621227}
[modify] https://crrev.com/da931601784415384334deb474cb85dc34a532d4/chrome/browser/chromeos/BUILD.gn
[delete] https://crrev.com/3eac43b1c7e2a82a58412346c3885d0c5f9bbd1b/chrome/browser/chromeos/proxy_cros_settings_parser.cc
[delete] https://crrev.com/3eac43b1c7e2a82a58412346c3885d0c5f9bbd1b/chrome/browser/chromeos/proxy_cros_settings_parser.h
[modify] https://crrev.com/da931601784415384334deb474cb85dc34a532d4/chromeos/network/proxy/ui_proxy_config.cc
[modify] https://crrev.com/da931601784415384334deb474cb85dc34a532d4/chromeos/network/proxy/ui_proxy_config.h
[modify] https://crrev.com/da931601784415384334deb474cb85dc34a532d4/chromeos/network/proxy/ui_proxy_config_service.cc
[modify] https://crrev.com/da931601784415384334deb474cb85dc34a532d4/chromeos/network/proxy/ui_proxy_config_service.h