[metacity] tile-preview: remove unneeded parameter

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 63b8a7d2cb2eef4ced74118abeab742518275bd7
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sun Jan 8 18:24:54 2017 +0200

    tile-preview: remove unneeded parameter

 src/core/screen.c          |    3 +--
 src/include/tile-preview.h |    2 +-
 src/ui/tile-preview.c      |    4 ++--
 3 files changed, 4 insertions(+), 5 deletions(-)
---
diff --git a/src/core/screen.c b/src/core/screen.c
index 9831a6e..ca6a3f2 100644
--- a/src/core/screen.c
+++ b/src/core/screen.c
@@ -1456,13 +1456,12 @@ meta_screen_tile_preview_update_timeout (gpointer data)
 {
   MetaScreen *screen = data;
   MetaWindow *window = screen->display->grab_window;
-  gboolean composited = screen->display->compositor != NULL;
   gboolean needs_preview = FALSE;
 
   screen->tile_preview_timeout_id = 0;
 
   if (!screen->tile_preview)
-    screen->tile_preview = meta_tile_preview_new (composited);
+    screen->tile_preview = meta_tile_preview_new ();
 
   if (window)
     {
diff --git a/src/include/tile-preview.h b/src/include/tile-preview.h
index bb7029e..c7f10bd 100644
--- a/src/include/tile-preview.h
+++ b/src/include/tile-preview.h
@@ -25,7 +25,7 @@
 
 typedef struct _MetaTilePreview MetaTilePreview;
 
-MetaTilePreview   *meta_tile_preview_new    (gboolean           composited);
+MetaTilePreview   *meta_tile_preview_new    (void);
 void               meta_tile_preview_free   (MetaTilePreview   *preview);
 void               meta_tile_preview_show   (MetaTilePreview   *preview,
                                              MetaRectangle     *rect);
diff --git a/src/ui/tile-preview.c b/src/ui/tile-preview.c
index 484c1af..ae45463 100644
--- a/src/ui/tile-preview.c
+++ b/src/ui/tile-preview.c
@@ -133,7 +133,7 @@ meta_tile_preview_composited_changed (GtkWidget *widget,
 }
 
 MetaTilePreview *
-meta_tile_preview_new (gboolean composited)
+meta_tile_preview_new (void)
 {
   MetaTilePreview *preview;
   GdkVisual *visual;
@@ -154,7 +154,7 @@ meta_tile_preview_new (gboolean composited)
   preview->tile_rect.x = preview->tile_rect.y = 0;
   preview->tile_rect.width = preview->tile_rect.height = 0;
 
-  preview->has_alpha = visual && composited;
+  preview->has_alpha = visual && gdk_screen_is_composited (screen);
 
   if (preview->has_alpha)
     {