Viewer:  https://mozilla.github.io/pdf.js/web/viewer.html
Chrome on Windows 10
When the attached PDF file is viewed, some of the fonts display as garbled text. 
[Arial, Courier, Times New Roman]
The file views correctly in Adobe Reader.
[fff.pdf](https://github.com/mozilla/pdf.js/files/4652174/fff.pdf)

return {
        version: ttf.getString(4),
        numTables: ttf.getUint16(),
        searchRange: ttf.getUint16(),
        entrySelector: ttf.getUint16(),
        rangeShift: ttf.getUint16(),
      };
    }
    function readTrueTypeCollectionHeader(ttc) {