Bug 1828463 - Make file migrator icon the same size as browser icons in the...

Bug 1828463 - Make file migrator icon the same size as browser icons in the browser-profile-selector dropdown. r=niklas,Itiel

Differential Revision: https://phabricator.services.mozilla.com/D175677

browser/components/migration/content/migration-wizard.mjs

@@ -475,6 +475,20 @@ export class MigrationWizard extends HTMLElement {
         button.style.backgroundImage = `url("chrome://global/skin/icons/defaultFavicon.svg")`;
       }
 
+      // Bug 1823489 - since the panel-list and panel-items are slotted, we
+      // cannot style them or their children in migration-wizard.css. We use
+      // inline styles for now to achieve the desired appearance, but bug 1823489
+      // will investigate having MigrationWizard own the <xul:panel>,
+      // <panel-list> and <panel-item>'s so that styling can be done in the
+      // stylesheet instead.
+      if (migrator.type == MigrationWizardConstants.MIGRATOR_TYPES.FILE) {
+        button.style.backgroundSize = "20px";
+        button.style.backgroundPosition = "6px center";
+        if (this.#browserProfileSelectorList.isDocumentRTL()) {
+          button.style.backgroundPositionX = "right 6px";
+        }
+      }
+
       if (migrator.profile) {
         document.l10n.setAttributes(
           opt,