data-device: Don't emit a signal for drag icon changes

The signal used to be in libwayland-server and the listener in weston, but
now they're both in the same file, so lets stop using signal.

src/compositor.h

@@ -476,12 +476,9 @@ struct weston_seat {
 	struct weston_surface *drag_surface;
 	struct wl_listener drag_surface_destroy_listener;
 	struct wl_listener drag_icon_listener;
-	struct wl_signal drag_icon_signal;
 
 	uint32_t num_tp;
 
-	struct wl_listener new_drag_icon_listener;
-
 	void (*led_update)(struct weston_seat *ws, enum weston_led leds);
 
 	struct weston_xkb_info xkb_info;

src/data-device.c

@@ -349,7 +349,7 @@ data_device_end_drag_grab(struct weston_seat *seat)
 {
 	if (seat->drag_surface) {
 		seat->drag_surface = NULL;
-		wl_signal_emit(&seat->drag_icon_signal, NULL);
+		weston_seat_update_drag_surface(seat, 0, 0);
 		wl_list_remove(&seat->drag_icon_listener.link);
 	}
 
@@ -451,7 +451,7 @@ data_device_start_drag(struct wl_client *client, struct wl_resource *resource,
 		seat->drag_icon_listener.notify = destroy_data_device_icon;
 		wl_signal_add(&icon_resource->destroy_signal,
 			      &seat->drag_icon_listener);
-		wl_signal_emit(&seat->drag_icon_signal, icon_resource);
+		weston_seat_update_drag_surface(seat, 0, 0);
 	}
 
 	weston_pointer_set_focus(seat->pointer, NULL,

src/input.c

@@ -1309,17 +1309,6 @@ bind_seat(struct wl_client *client, void *data, uint32_t version, uint32_t id)
 	wl_seat_send_capabilities(resource, caps);
 }
 
-static void
-device_handle_new_drag_icon(struct wl_listener *listener, void *data)
-{
-	struct weston_seat *seat;
-
-	seat = container_of(listener, struct weston_seat,
-			    new_drag_icon_listener);
-
-	weston_seat_update_drag_surface(seat, 0, 0);
-}
-
 int
 weston_compositor_xkb_init(struct weston_compositor *ec,
 			   struct xkb_rule_names *names)
@@ -1520,7 +1509,6 @@ weston_seat_init(struct weston_seat *seat, struct weston_compositor *ec)
 	wl_list_init(&seat->base_resource_list);
 	wl_signal_init(&seat->selection_signal);
 	wl_list_init(&seat->drag_resource_list);
-	wl_signal_init(&seat->drag_icon_signal);
 	wl_signal_init(&seat->destroy_signal);
 
 	seat->has_pointer = 0;
@@ -1541,10 +1529,6 @@ weston_seat_init(struct weston_seat *seat, struct weston_compositor *ec)
 
 	wl_list_insert(ec->seat_list.prev, &seat->link);
 
-	seat->new_drag_icon_listener.notify = device_handle_new_drag_icon;
-	wl_signal_add(&seat->drag_icon_signal,
-		      &seat->new_drag_icon_listener);
-
 	clipboard_create(seat);
 
 	wl_signal_emit(&ec->seat_created_signal, seat);