[gnome-shell] overview: Synchronize panel opacity with overview leave animation

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

commit 76836fe3888f6ee85aa2b18b2b711d2f388ca2c2
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed Feb 17 00:57:13 2021 +0100

    overview: Synchronize panel opacity with overview leave animation
    
    Gestures leaving the overview from a short distance result in an
    ugly effect with the panel opacity transitionhaving a fixed duration.
    Make this transition have the same duration (although in a hackish
    way) so we avoid the ugly effect.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1643>

 js/ui/overview.js | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/js/ui/overview.js b/js/ui/overview.js
index 6fbc39b4e1..3f881da57f 100644
--- a/js/ui/overview.js
+++ b/js/ui/overview.js
@@ -397,6 +397,7 @@ var Overview = class {
         if (endProgress === 0) {
             this._shown = false;
             this.emit('hiding');
+            Main.panel.style = 'transition-duration: %dms;'.format(duration);
             onComplete = () => this._hideDone();
         } else {
             onComplete = () => this._showDone();
@@ -626,6 +627,8 @@ var Overview = class {
         else
             Main.layoutManager.hideOverview();
 
+        Main.panel.style = null;
+
         this._syncGrab();
     }