[gtk/wip/carlosg/scroll-controller-fixes: 1/2] scrollcontroller: Set scroll event mask on scroll controller

[Carlos Garnacho <carlosg src gnome org>]

commit ebd1840802a11f1f0b668064f4ba3c014c47c045
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon Oct 21 17:09:17 2019 +0200

    scrollcontroller: Set scroll event mask on scroll controller
    
    This ensures adding the controller to a widget will end up with
    the expected event masks in the widget default window.

 gtk/gtkeventcontrollerscroll.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/gtk/gtkeventcontrollerscroll.c b/gtk/gtkeventcontrollerscroll.c
index 91831f404f..9e90b54dd7 100644
--- a/gtk/gtkeventcontrollerscroll.c
+++ b/gtk/gtkeventcontrollerscroll.c
@@ -455,6 +455,9 @@ gtk_event_controller_scroll_init (GtkEventControllerScroll *scroll)
 {
   scroll->scroll_history = g_array_new (FALSE, FALSE,
                                         sizeof (ScrollHistoryElem));
+  gtk_event_controller_set_event_mask (GTK_EVENT_CONTROLLER (scroll),
+                                       GDK_SCROLL_MASK |
+                                       GDK_SMOOTH_SCROLL_MASK);
 }
 
 /**