So clients of the view can know if the view is busy.
https://bugzilla.gnome.org/show_bug.cgi?id=753786
036ba25 gtkplacesview: add a loading property
gtk/gtkplacesview.c | 39 +++++++++++++++++++++++++++++++++++++++
gtk/gtkplacesviewprivate.h | 3 +++
2 files changed, 42 insertions(+)
Upstream: git.gnome.org