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)

this.cidEncoding.startsWith("Identity-")
    ) {
      const GlyphMapForStandardFonts = getGlyphMapForStandardFonts(),
        cidToGidMap = properties.cidToGidMap;
      
      
      const map = [];
      for (const charCode in GlyphMapForStandardFonts) {
        map[+charCode] = GlyphMapForStandardFonts[charCode];
      }
      if (/Arial-?Black/i.test(name)) {
        const SupplementalGlyphMapForArialBlack =
          getSupplementalGlyphMapForArialBlack();
        for (const charCode in SupplementalGlyphMapForArialBlack) {
          map[+charCode] = SupplementalGlyphMapForArialBlack[charCode];
        }
      } else if (/Calibri/i.test(name)) {
        const SupplementalGlyphMapForCalibri =
          getSupplementalGlyphMapForCalibri();
        for (const charCode in SupplementalGlyphMapForCalibri) {
          map[+charCode] = SupplementalGlyphMapForCalibri[charCode];
        }
      }
      
      
      if (cidToGidMap) {
        for (const charCode in map) {
          const cid = map[charCode];
          if (cidToGidMap[cid] !== undefined) {
            map[+charCode] = cidToGidMap[cid];