Bug 1777612 - Use page-icon:https://example.com/ to load favicons r=sfoster,desktop-theme-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D150844

browser/themes/shared/autocomplete.css

@@ -88,7 +88,6 @@
 #PopupAutoComplete > richlistbox > richlistitem[originaltype="loginWithOrigin"] > .two-line-wrapper > .ac-site-icon,
 #PopupAutoComplete > richlistbox > richlistitem[originaltype="login"] > .ac-site-icon {
   fill: GrayText;
-  list-style-image: url(chrome://browser/skin/login.svg);
 }
 
 #PopupAutoComplete > richlistbox > richlistitem[originaltype="importableLogins"] > .two-line-wrapper > .ac-site-icon {

toolkit/content/widgets/autocomplete-richlistitem.js

@@ -688,6 +688,9 @@
 
       let details = JSON.parse(this.getAttribute("ac-label"));
       this.querySelector(".line2-label").textContent = details.comment;
+      this.querySelector(
+        ".ac-site-icon"
+      ).src = `page-icon:${details.login?.origin}`;
     }
   }