32434 Support for replacing the TabController, after disposing the old one (cla: yes, f: material design, framework)

32437 Add assert that the root widget has been attached. (a: tests, cla: yes, framework)

32444 Updated some links (cla: yes, framework, tool)

32469  Let CupertinoNavigationBarBackButton take a custom onPressed (cla: yes, f: cupertino, framework)

32470 Revert “Cupertino localization step 12: push translation for all supported languages” (cla: yes)

32487 Add a more meaningful message to the assertion on children (cla: yes, framework)

32496 Revert “Add more asserts to check matrix validity” (cla: yes)

32499 Use precisionErrorTolerance (cla: yes)