[gtk+] mountoperation: Update to using GdkEvent API

[Carlos Garnacho <carlosg src gnome org>]

commit 46336aaebee7e41d0cf02f3747976f010a25bccf
Author: Carlos Garnacho <carlosg gnome org>
Date:   Fri Aug 25 16:50:14 2017 +0200

    mountoperation: Update to using GdkEvent API

 gtk/gtkmountoperation.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)
---
diff --git a/gtk/gtkmountoperation.c b/gtk/gtkmountoperation.c
index 2f5189d..0979bd0 100644
--- a/gtk/gtkmountoperation.c
+++ b/gtk/gtkmountoperation.c
@@ -1290,6 +1290,7 @@ do_popup_menu_for_process_tree_view (GtkWidget         *widget,
 {
   GtkWidget *menu;
   GtkWidget *item;
+  gdouble x, y;
 
   menu = gtk_menu_new ();
   gtk_style_context_add_class (gtk_widget_get_style_context (menu),
@@ -1302,14 +1303,15 @@ do_popup_menu_for_process_tree_view (GtkWidget         *widget,
   gtk_menu_shell_append (GTK_MENU_SHELL (menu), item);
   gtk_widget_show (menu);
 
-  if (event && gdk_event_triggers_context_menu (event))
+  if (event && gdk_event_triggers_context_menu (event) &&
+      gdk_event_get_coords (event, &x, &y))
     {
       GtkTreePath *path;
       GtkTreeSelection *selection;
 
       if (gtk_tree_view_get_path_at_pos (GTK_TREE_VIEW (op->priv->process_tree_view),
-                                         (gint) event->button.x,
-                                         (gint) event->button.y,
+                                         (gint) x,
+                                         (gint) y,
                                          &path,
                                          NULL,
                                          NULL,