[mutter/gnome-3-28] wayland/surface: Add API to cache frame callbacks

[Olivier Fourdan <ofourdan src gnome org>]

commit 4dfe4256ae66a151fb5a570f34af0f85f3e5e0f5
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Aug 27 12:05:58 2018 +0200

    wayland/surface: Add API to cache frame callbacks
    
    Sometimes it may be useful for roles to put callbacks in the generic
    surface frame callback queue. The surface frame callback queue will
    either eventually be processed on the next surface role assignment that
    places the frame callbacks in a role specific queue, processed at some
    other point in time by a role, or cleaned up on surface destruction.
    
    https://gitlab.gnome.org/GNOME/mutter/issues/240
    (cherry picked from commit 0ace58d05f3e50f4fdcf4971baab163e6ae5a1e9)

 src/wayland/meta-wayland-surface.c | 17 ++++++++++-------
 src/wayland/meta-wayland-surface.h |  3 +++
 2 files changed, 13 insertions(+), 7 deletions(-)
---
diff --git a/src/wayland/meta-wayland-surface.c b/src/wayland/meta-wayland-surface.c
index d2f5ffccf..3c9a404c7 100644
--- a/src/wayland/meta-wayland-surface.c
+++ b/src/wayland/meta-wayland-surface.c
@@ -602,6 +602,15 @@ parent_surface_state_applied (gpointer data,
   meta_wayland_subsurface_parent_state_applied (subsurface);
 }
 
+void
+meta_wayland_surface_cache_pending_frame_callbacks (MetaWaylandSurface      *surface,
+                                                    MetaWaylandPendingState *pending)
+{
+  wl_list_insert_list (&surface->pending_frame_callback_list,
+                       &pending->frame_callback_list);
+  wl_list_init (&pending->frame_callback_list);
+}
+
 void
 meta_wayland_surface_apply_pending_state (MetaWaylandSurface      *surface,
                                           MetaWaylandPendingState *pending)
@@ -722,13 +731,7 @@ meta_wayland_surface_apply_pending_state (MetaWaylandSurface      *surface,
     }
   else
     {
-      /* Since there is no role assigned to the surface yet, keep frame
-       * callbacks queued until a role is assigned and we know how
-       * the surface will be drawn.
-       */
-      wl_list_insert_list (&surface->pending_frame_callback_list,
-                           &pending->frame_callback_list);
-      wl_list_init (&pending->frame_callback_list);
+      meta_wayland_surface_cache_pending_frame_callbacks (surface, pending);
 
       if (pending->newly_attached)
         {
diff --git a/src/wayland/meta-wayland-surface.h b/src/wayland/meta-wayland-surface.h
index 05d2a0a24..46accd900 100644
--- a/src/wayland/meta-wayland-surface.h
+++ b/src/wayland/meta-wayland-surface.h
@@ -261,6 +261,9 @@ MetaWaylandSurface *meta_wayland_surface_get_toplevel (MetaWaylandSurface *surfa
 
 MetaWindow *        meta_wayland_surface_get_toplevel_window (MetaWaylandSurface *surface);
 
+void                meta_wayland_surface_cache_pending_frame_callbacks (MetaWaylandSurface      *surface,
+                                                                        MetaWaylandPendingState *pending);
+
 void                meta_wayland_surface_queue_pending_frame_callbacks (MetaWaylandSurface *surface);
 
 void                meta_wayland_surface_queue_pending_state_frame_callbacks (MetaWaylandSurface      
*surface,