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)

strBuf.length = stringLength;
            for (i = 0; i < stringLength; ++i) {
              strBuf[i] = String.fromCharCode(font.getByte());
            }
            customNames.push(strBuf.join(""));
          }
          glyphNames = [];
          for (i = 0; i < numGlyphs; ++i) {
            const j = glyphNameIndexes[i];
            if (j < 258) {
              glyphNames.push(MacStandardGlyphOrdering[j]);
              continue;
            }
            glyphNames.push(customNames[j - 258]);
          }
          break;
        case 0x00030000:
          break;
        default:
          warn("Unknown/unsupported post table version " + version);
          valid = false;
          if (propertiesObj.defaultEncoding) {
            glyphNames = propertiesObj.defaultEncoding;
          }
          break;
      }
      propertiesObj.glyphNames = glyphNames;
      return valid;
    }
    function readNameTable(nameTable) {