67938 [Material] Parent checkbox in DataTable should deselect all, if children checkboxes are disabled or selected  (cla: yes, f: material design, framework, waiting for tree to go green)

67946 Migrate Scaffold SnackBars in the framework to ScaffoldMessenger (a: tests, cla: yes, d: api docs, d: examples, documentation, f: material design, framework, team, waiting for tree to go green)

67947 Deprecate old SnackBar methods (cla: yes, f: material design, framework, severe: API break, severe: new feature, waiting for tree to go green)

68000 Provide a way to change the default PopupMenuButton’s icon size (cla: yes, f: material design, framework, waiting for tree to go green)