1a20701542
We have a function, OverflowableToolbar.findOverflowedInsertionPoints, whose job it is to compute the right insertion point for a widget if the widget is being inserted into an overflowable toolbar. That function failed to account for the possibility that the widget was a browser action, and would return the #defaultList instead of the #webExtList if the item was overflowing. This patch checks the ID of the widget first, and then supplies the correct list. Differential Revision: https://phabricator.services.mozilla.com/D162586