remoteMenu: Port to GtkMenuTrackerItem

This pulls in new upstream API that Ryan will maintain, removing
code on our side.

Currently, our implementation of submenus will be gone, but this
will be fixed in a few commits.

https://bugzilla.gnome.org/show_bug.cgi?id=700257

src/shell-menu-tracker.c

@@ -25,6 +25,12 @@
 #include "shell-menu-tracker.h"
 #include "gtkmenutracker.h"
 
+/**
+ * SECTION:shell-menu-tracker
+ * @short_description: a simple wrapper around #GtkMenuTracker
+ *                     to make it bindable.
+ */
+
 struct _ShellMenuTracker
 {
   guint ref_count;
@@ -40,17 +46,12 @@ struct _ShellMenuTracker
 };
 
 static void
-shell_menu_tracker_insert_func (gint position,
-                                GMenuModel *model,
-                                gint item_index,
-                                const gchar *action_namespace,
-                                gboolean is_separator,
+shell_menu_tracker_insert_func (GtkMenuTrackerItem *item,
+                                gint position,
                                 gpointer user_data)
 {
   ShellMenuTracker *tracker = (ShellMenuTracker *) user_data;
-  tracker->insert_func (position, model, item_index,
-                        action_namespace, is_separator,
-                        tracker->insert_user_data);
+  tracker->insert_func (item, position, tracker->insert_user_data);
 }
 
 static void
@@ -63,6 +64,7 @@ shell_menu_tracker_remove_func (gint position,
 
 /**
  * shell_menu_tracker_new:
+ * @observable:
  * @model:
  * @action_namespace: (allow-none):
  * @insert_func:
@@ -73,7 +75,8 @@ shell_menu_tracker_remove_func (gint position,
  * @remove_notify:
  */
 ShellMenuTracker *
-shell_menu_tracker_new (GMenuModel                 *model,
+shell_menu_tracker_new (GtkActionObservable        *observable,
+                        GMenuModel                 *model,
                         const gchar                *action_namespace,
                         ShellMenuTrackerInsertFunc  insert_func,
                         gpointer                    insert_user_data,
@@ -92,7 +95,8 @@ shell_menu_tracker_new (GMenuModel                 *model,
   tracker->remove_user_data = remove_user_data;
   tracker->remove_notify = remove_notify;
 
-  tracker->tracker = gtk_menu_tracker_new (model,
+  tracker->tracker = gtk_menu_tracker_new (observable,
+                                           model,
                                            TRUE, /* with separators */
                                            action_namespace,
                                            shell_menu_tracker_insert_func,