They're deprecating XUL and the NPAPI plugin architecture so that they can move to servo relatively legacy free. Importing Chrome's SWF and PDF is a way to str

They're deprecating XUL and the NPAPI plugin architecture so that they can move to servo relatively legacy free. Importing Chrome's SWF and PDF is a way to stress test their new plugin implementation. Not maintaining pdf.js seems a budgeting decision but Flash is restoring functionality to Linux via a cross-browser plugin, which Adobe had abandoned for Chrome only.