[gtk+] places sidebar: Document style classes

[Matthias Clasen <matthiasc src gnome org>]

commit cd798d5aed6b008d39eba8f31d0823075988edc8
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Nov 5 10:51:54 2015 -0500

    places sidebar: Document style classes
    
    Document the style classes that GtkPlacesSidebar uses on its rows.

 gtk/gtkplacessidebar.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkplacessidebar.c b/gtk/gtkplacessidebar.c
index a34ae67..19e171d 100644
--- a/gtk/gtkplacessidebar.c
+++ b/gtk/gtkplacessidebar.c
@@ -95,6 +95,12 @@
  *
  * GtkPlacesSidebar uses a single CSS node with name placesidebar and style
  * class .sidebar.
+ *
+ * Among the children of the places sidebar, the following style classes can
+ * be used:
+ * - .sidebar-new-bookmark-row for the 'Add new bookmark' row
+ * - .sidebar-placeholder-row for a row that is a placeholder
+ * - .has-open-popup when a popup is open for a row
  */
 
 /* These are used when a destination-side DND operation is taking place.