[mutter] shaped-texture: Don't clear mipmaps during painting

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

commit bb1ffb08870012844b35e05639e19f631cfc9245
Author: Daniel van Vugt <daniel van vugt canonical com>
Date:   Tue Aug 30 16:16:38 2022 +0800

    shaped-texture: Don't clear mipmaps during painting
    
    This reverts an attempt at saving texture memory that was introduced
    recently in 16fa2100. It was misguided because the same texture may be
    needed in the next frame if a window has multiple previews visible on
    screen at once (gnome-shell's overview). Keeping the mipmaps around
    seems to reduce the peak render times of the overview by roughly 5%-10%.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2598>

 src/compositor/meta-shaped-texture.c | 3 ---
 1 file changed, 3 deletions(-)
---
diff --git a/src/compositor/meta-shaped-texture.c b/src/compositor/meta-shaped-texture.c
index bea77c1a11..b3e087af9a 100644
--- a/src/compositor/meta-shaped-texture.c
+++ b/src/compositor/meta-shaped-texture.c
@@ -635,9 +635,6 @@ do_paint_content (MetaShapedTexture   *stex,
     {
       min_filter = COGL_PIPELINE_FILTER_NEAREST;
       mag_filter = COGL_PIPELINE_FILTER_NEAREST;
-
-      /* Back to normal desktop viewing. Save some memory */
-      meta_texture_mipmap_clear (stex->texture_mipmap);
     }
   else
     {