[gnome-shell] Background: Drop "saturation" related source

[Rico Tzschichholz <ricotz src gnome org>]

commit d519c7263e7e0c322f4f86ecba637d22d0307fee
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Wed Sep 18 13:45:23 2013 +0200

    Background: Drop "saturation" related source
    
    "saturation" was removed from MetaBackground in mutter with
    https://git.gnome.org/browse/mutter/commit/?id=0e589061

 js/ui/background.js |   22 ----------------------
 1 files changed, 0 insertions(+), 22 deletions(-)
---
diff --git a/js/ui/background.js b/js/ui/background.js
index 41e67fe..c50ae29 100644
--- a/js/ui/background.js
+++ b/js/ui/background.js
@@ -315,7 +315,6 @@ const Background = new Lang.Class({
 
         this._brightness = 1.0;
         this._vignetteSharpness = 0.2;
-        this._saturation = 1.0;
         this._cancellable = new Gio.Cancellable();
         this.isLoaded = false;
 
@@ -416,7 +415,6 @@ const Background = new Lang.Class({
     },
 
     _addImage: function(content, index, filename) {
-        content.saturation = this._saturation;
         content.brightness = this._brightness;
         content.vignette_sharpness = this._vignetteSharpness;
 
@@ -432,7 +430,6 @@ const Background = new Lang.Class({
     },
 
     _updateImage: function(content, index, filename) {
-        content.saturation = this._saturation;
         content.brightness = this._brightness;
         content.vignette_sharpness = this._vignetteSharpness;
 
@@ -590,24 +587,6 @@ const Background = new Lang.Class({
         this._loadFile(filename);
     },
 
-    get saturation() {
-        return this._saturation;
-    },
-
-    set saturation(saturation) {
-        this._saturation = saturation;
-
-        if (this._pattern && this._pattern.content)
-            this._pattern.content.saturation = saturation;
-
-        let keys = Object.keys(this._images);
-        for (let i = 0; i < keys.length; i++) {
-            let image = this._images[keys[i]];
-            if (image && image.content)
-                image.content.saturation = saturation;
-        }
-    },
-
     get brightness() {
         return this._brightness;
     },
@@ -751,7 +730,6 @@ const BackgroundManager = new Lang.Class({
         let newBackground = this._createBackground(monitorIndex);
         newBackground.vignetteSharpness = background.vignetteSharpness;
         newBackground.brightness = background.brightness;
-        newBackground.saturation = background.saturation;
         newBackground.visible = background.visible;
 
         newBackground.loadedSignalId = newBackground.connect('loaded',