[gnome-games] ui: Explain usage of cancellables in ApplicationWindow

[Adrien Plazas <aplazas src gnome org>]

commit 106e4f64ec063534f1d96b22d95f7a9cc83ae9e4
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Wed Aug 17 13:02:44 2016 +0200

    ui: Explain usage of cancellables in ApplicationWindow
    
    https://bugzilla.gnome.org/show_bug.cgi?id=769993

 src/ui/application-window.vala |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/src/ui/application-window.vala b/src/ui/application-window.vala
index 5b6f097..4b0f514 100644
--- a/src/ui/application-window.vala
+++ b/src/ui/application-window.vala
@@ -75,6 +75,10 @@ private class Games.ApplicationWindow : Gtk.ApplicationWindow {
 
        private HashTable<Game, Runner> runners;
 
+       // These allow to cancel dialogs.
+       // They are usefull when trying to run a game or to quit the
+       // application from an external source (the application menu, the
+       // command line...).
        private Cancellable run_game_cancellable;
        private Cancellable quit_game_cancellable;