If the inspector was opened from the Inspect context menu, the node gets selected in the MarkupView constructor, but the Toolbox focuses the Inspector iframe once the tool is loaded (and the iframe is actually visible), so we need to focus the selected node after the inspector was properly selected and focused. Original Revision: https://phabricator.services.mozilla.com/D259039 Differential Revision: https://phabricator.services.mozilla.com/D260236