[mutter] tests/wayland: Make create_shm_buffer() public

[Marge Bot <marge-bot src gnome org>]

commit fd7ee33337b4d78321194ccbc6b6473a6af1355a
Author: Robert Mader <robert mader collabora com>
Date:   Mon May 23 11:05:10 2022 +0200

    tests/wayland: Make create_shm_buffer() public
    
    It will be needed in a following commit.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1055>

 src/tests/wayland-test-clients/wayland-test-client-utils.c | 2 +-
 src/tests/wayland-test-clients/wayland-test-client-utils.h | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)
---
diff --git a/src/tests/wayland-test-clients/wayland-test-client-utils.c 
b/src/tests/wayland-test-clients/wayland-test-client-utils.c
index 19ddd2861a..c8029cf069 100644
--- a/src/tests/wayland-test-clients/wayland-test-client-utils.c
+++ b/src/tests/wayland-test-clients/wayland-test-client-utils.c
@@ -280,7 +280,7 @@ static const struct wl_buffer_listener buffer_listener = {
   handle_buffer_release
 };
 
-static gboolean
+gboolean
 create_shm_buffer (WaylandDisplay    *display,
                    int                width,
                    int                height,
diff --git a/src/tests/wayland-test-clients/wayland-test-client-utils.h 
b/src/tests/wayland-test-clients/wayland-test-client-utils.h
index 533846980d..dc169cdf4f 100644
--- a/src/tests/wayland-test-clients/wayland-test-client-utils.h
+++ b/src/tests/wayland-test-clients/wayland-test-client-utils.h
@@ -40,6 +40,13 @@ int create_anonymous_file (off_t size);
 
 WaylandDisplay * wayland_display_new (WaylandDisplayCapabilities capabilities);
 
+gboolean create_shm_buffer (WaylandDisplay    *display,
+                            int                width,
+                            int                height,
+                            struct wl_buffer **out_buffer,
+                            void             **out_data,
+                            int               *out_size);
+
 void draw_surface (WaylandDisplay    *display,
                    struct wl_surface *surface,
                    int                width,