[gnome-shell] perf: fix wallpaper style for overridden background

[Owen Taylor <otaylor src gnome org>]

commit c93767768ce9a29f228f4c2ad8d68683610c7ea2
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Mon Aug 25 09:48:19 2014 -0400

    perf: fix wallpaper style for overridden background
    
    The code that loads SHELL_BACKGROUND_IMAGE, which is used to load the
    performance background was loading it in WALLPAPER mode, not ZOOM
    mode. Zoom mode is what we use for the actual GNOME defaultiwallpaper
    and what we want to test: the background will be scaled except when
    the resolution matches the 2560x1440 default backgrounds.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=735385

 js/ui/background.js |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/js/ui/background.js b/js/ui/background.js
index 3fe0b7a..27ce124 100644
--- a/js/ui/background.js
+++ b/js/ui/background.js
@@ -587,7 +587,7 @@ const Background = new Lang.Class({
         let filename;
         if (this._overrideImage != null) {
             filename = this._overrideImage;
-            this._style = GDesktopEnums.BackgroundStyle.WALLPAPER; // Hardcode
+            this._style = GDesktopEnums.BackgroundStyle.ZOOM; // Hardcode
         } else {
             this._style = this._settings.get_enum(BACKGROUND_STYLE_KEY);
             if (this._style == GDesktopEnums.BackgroundStyle.NONE) {