[gnome-shell] background: free MetaBackground explicitly when its MetaBackgroundActor is destroyed

[Rui Matos <rtcm src gnome org>]

commit e72d388a674d4f7c42f5b532ffd9c43aa29bcc27
Author: Hyungwon Hwang <hyungwon hwang7 gmail com>
Date:   Fri Jun 10 19:34:48 2016 +0900

    background: free MetaBackground explicitly when its MetaBackgroundActor is destroyed
    
    The memory which MetaBackground resides is freed automatically, when its
    wrapper object Background is freed by garbage collection. But because the
    memory for MetaBackground is huge, changing the background or changing the
    background mode repeatedly makes a lot of memory to be in use until garbage
    collection runs.
    
    This patch frees the MetaBackground object explicitly when its
    MetaBackgroundActor is destroyed which is the moment that the memory in the
    object is not used anymore.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=766353
    
    Signed-off-by: Hyungwon Hwang <hyungwon hwang7 gmail com>

 js/ui/background.js |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/js/ui/background.js b/js/ui/background.js
index 5db1e6c..762c76c 100644
--- a/js/ui/background.js
+++ b/js/ui/background.js
@@ -696,6 +696,7 @@ const BackgroundManager = new Lang.Class({
                            time: FADE_ANIMATION_TIME,
                            transition: 'easeOutQuad',
                            onComplete: function() {
+                               oldBackgroundActor.background.run_dispose();
                                oldBackgroundActor.destroy();
                            }
                          });