... if we're not using indicators and the policy may be visible. Not
doing this if the policy may be invisible is incorrect as we need to
reserve the space anyway in case the scrolledwindow is allocated at
minimum size and the child size increases to show the scrollbar.
It was only testing the default configuration, where overlay scrolling
is on and both scrollbars use POLICY_AUTOMATIC. We should also test the
other 3 configurations that are available by including non-overlay
scrollbars and/or those that use POLICY_ALWAYS.
https://bugzilla.gnome.org/show_bug.cgi?id=778853
It was only testing the default configuration where overlay-scrolling is
TRUE and the policy is POLICY_AUTOMATIC. We should also test FALSE and
POLICY_ALWAYS. This commit adds those tests and makes the !overlay &&
POLICY_ALWAYS case pass by excluding the size of the relevant scrollbar,
as we are only interested in whether the content size is as requested.
https://bugzilla.gnome.org/show_bug.cgi?id=778853
The maximum content size does not increase the minimum request
but only ensures that both minimum and natural requests do not
exceed the maximum setting.
