Bug 1766811 - [devtools] Remove StyleEditor list item animation. r=jdescottes.

Differential Revision: https://phabricator.services.mozilla.com/D144930

devtools/client/styleeditor/test/head.js

@@ -89,10 +89,6 @@ var openStyleEditor = async function(tab) {
   const panel = toolbox.getPanel("styleeditor");
   const ui = panel.UI;
 
-  // The stylesheet list appears with an animation. Let this animation finish.
-  const animations = ui._root.getAnimations({ subtree: true });
-  await Promise.all(animations.map(a => a.finished));
-
   return { toolbox, panel, ui };
 };
 

devtools/client/themes/splitview.css

@@ -11,16 +11,6 @@
   --sidemenu-selected-arrow-rtl: url(images/item-arrow-rtl.svg);
 }
 
-/* Loading animation */
-@keyframes item-load {
-  0% {
-    transform: scaleY(0) translateY(-100%);
-  }
-  100% {
-    transform: none;
-  }
-}
-
 box,
 .splitview-nav {
   -moz-box-flex: 1;
@@ -35,13 +25,11 @@ box,
 }
 
 .splitview-nav > li {
-  animation: item-load .5s var(--animation-curve);
   padding-inline-end: 8px;
   -moz-box-align: center;
   outline: 0;
   vertical-align: bottom;
   border-bottom: 1px solid var(--theme-splitter-color);
-  background: inherit;
 }
 
 .placeholder {