[gtk+] Remove an outdated comment

[Matthias Clasen <matthiasc src gnome org>]

commit 88248e34b1bf55c435b908cfe3fc831f18b87f18
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Aug 19 23:24:08 2016 -0400

    Remove an outdated comment
    
    It described as TODO what the code right below it already does.

 gdk/wayland/gdkglcontext-wayland.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
---
diff --git a/gdk/wayland/gdkglcontext-wayland.c b/gdk/wayland/gdkglcontext-wayland.c
index b43b9b6..7733188 100644
--- a/gdk/wayland/gdkglcontext-wayland.c
+++ b/gdk/wayland/gdkglcontext-wayland.c
@@ -235,7 +235,6 @@ gdk_wayland_gl_context_end_frame (GdkGLContext   *context,
   egl_surface = gdk_wayland_window_get_egl_surface (window->impl_window,
                                                     context_wayland->egl_config);
 
-  /* TODO: Use eglSwapBuffersWithDamageEXT if available */
   if (display_wayland->have_egl_swap_buffers_with_damage)
     {
       int i, j, n_rects = cairo_region_num_rectangles (damage);