This was done by reviewing the results of https://searchfox.org/mozilla-central/search?q=%2F*GetAttr%5C(.%2B(%26%26%7C%5C%7C%5C%7C)&case=true®exp=true one by one and replacing them with Element::HasNonEmptyAttr if possible. Differential Revision: https://phabricator.services.mozilla.com/D51241