Bug 1908431 - add basic support for tab groups in overflow menu. r=dao,fluent-reviewers,desktop-theme-reviewers,tabbrowser-reviewers,bolsson

Differential Revision: https://phabricator.services.mozilla.com/D232389

browser/components/tabbrowser/content/tabgroup.js

@@ -138,6 +138,15 @@
       this.#updateLabelAriaAttributes();
     }
 
+    // alias for label
+    get name() {
+      return this.label;
+    }
+
+    set name(newName) {
+      this.label = newName;
+    }
+
     get collapsed() {
       return this.hasAttribute("collapsed");
     }
@@ -224,6 +233,19 @@
     on_TabSelect() {
       this.collapsed = false;
     }
+
+    /**
+     * If one of this group's tabs is the selected tab, this will do nothing.
+     * Otherwise, it will expand the group if collapsed, and select the first
+     * tab in its list.
+     */
+    select() {
+      this.collapsed = false;
+      if (gBrowser.selectedTab.group == this) {
+        return;
+      }
+      gBrowser.selectedTab = this.tabs[0];
+    }
   }
 
   customElements.define("tab-group", MozTabbrowserTabGroup);