1) checkBrokenScripts(complex.sfx2.UndoManager)
java.lang.NullPointerException
    at complex.sfx2.UndoManager.impl_clickButton(UndoManager.java:432)
    at complex.sfx2.UndoManager.checkBrokenScripts(UndoManager.java:188)

impl_clickButton() gets the wrong accessible object and throws.

The .uno:SwitchControlDesignMode is dispatched async, so make sure
it's processesed before trying to click the button.

See UnoControl::getAccessibleContext() "in design mode, use a fallback".

This was running in "rr record --chaos".

Change-Id: Iee9f25c2fff56d32e6b579b5d44ee6df9870fd8b