Bug 1913053 - Use the sidebar text color along with the fallback back…

…ground on selected rows for themes not setting highlight colors. r=nsharpley,emilio,desktop-theme-reviewers a=RyanVM

Differential Revision: https://phabricator.services.mozilla.com/D219227

browser/base/content/contentTheme.js

@@ -114,11 +114,10 @@
       {
         lwtProperty: "sidebar_highlight",
         processColor(rgbaChannels, element) {
+          element.toggleAttribute("lwt-sidebar-highlight", !!rgbaChannels);
           if (!rgbaChannels) {
-            element.removeAttribute("lwt-sidebar-highlight");
             return null;
           }
-          element.setAttribute("lwt-sidebar-highlight", "true");
 
           const { r, g, b, a } = rgbaChannels;
           return `rgba(${r}, ${g}, ${b}, ${a})`;

browser/themes/shared/places/sidebar.css

@@ -29,11 +29,11 @@
   color-scheme: dark;
 }
 
-.sidebar-panel[lwt-sidebar] .sidebar-placesTreechildren::-moz-tree-row(selected) {
-  background-color: light-dark(hsla(0,0%,80%,.3), rgba(249,249,250,.1));
-}
+.sidebar-panel[lwt-sidebar] .sidebar-placesTreechildren {
+  &::-moz-tree-row(selected) {
+    background-color: light-dark(hsla(0,0%,80%,.3), rgba(249,249,250,.1));
+  }
 
-.sidebar-panel[lwt-sidebar="dark"] .sidebar-placesTreechildren {
   &::-moz-tree-image(selected),
   &::-moz-tree-twisty(selected),
   &::-moz-tree-cell-text(selected) {
@@ -42,7 +42,7 @@
 }
 
 .sidebar-panel[lwt-sidebar-highlight] .sidebar-placesTreechildren {
-  &::-moz-tree-row(selected,focus) {
+  &::-moz-tree-row(selected, focus) {
     background-color: var(--lwt-sidebar-highlight-background-color);
   }