Please see: https://bugzilla.mozilla.org/show_bug.cgi?id=1440284 https://hg.mozilla.org/mozilla-central/rev/b599a95ce057 For consistency, the patch also updates the `PdfJsTelemetry-stub.jsm` file.
This is the PDF.js project output, https://github.com/mozilla/pdf.js Current extension version is: PDFJSSCRIPT_VERSION Taken from upstream commit: PDFJSSCRIPT_COMMIT