Michael Catanzaro authored Nov 08, 2019 and Jan-Michael Brummer committed Nov 12, 2019

Our scheme to sync settings from the host to the web process extension
has failed, because it depended on the web process's ability to read
host settings: i.e. its design never actually worked, since the whole
purpose was to avoid depending on host settings, which are inaccessible
inside the sandbox.

Instead of fixing this, we can just not allow the web process to read
Epiphany settings at all. Toolkit level settings should go through
either XSettings or xdg-desktop-portal. Add an assertion to ensure the
web process crashes if it tries to use ephy_settings_get() to avoid
mistakes here.

Currently we use two settings: do-not-track, and remember-passwords. We
can remove the do-not-track setting and just always strip tracking query
parameters from URLs, especially since this setting is hidden since 3.34
anyway. In the future, we'll want to remove this code and let ITP do its
thing instead. As for remember-passwords, we can manually sync the state
of this setting to the web process using D-Bus.

Finally, remove the unused browser_mode variable.

Note this goes a long way to fixing #865, because we no longer use a
custom GKeyfileSettingsBackend for web process permissions. Also note
the removed code was leaking a GKeyfileSettingsBackend, contributing to
inotify overuse.

Fixes #993