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)

);
      if (
        type === "CIDFontType2" &&
        !this.cidEncoding.startsWith("Identity-") &&
        !(this.toUnicode instanceof IdentityToUnicodeMap)
      ) {
        this.toUnicode.forEach(function (charCode, unicodeCharCode) {
          map[+charCode] = unicodeCharCode;
        });
      }
      this.toFontChar = map;
    } else {
      const glyphsUnicodeMap = getGlyphsUnicode();
      const map = [];
      this.toUnicode.forEach((charCode, unicodeCharCode) => {
        if (!this.composite) {
          const glyphName =
            this.differences[charCode] || this.defaultEncoding[charCode];
          const unicode = getUnicodeForGlyph(glyphName, glyphsUnicodeMap);
          if (unicode !== -1) {
            unicodeCharCode = unicode;
          }
        }
        map[+charCode] = unicodeCharCode;
      });
      
      
      if (this.composite && this.toUnicode instanceof IdentityToUnicodeMap) {
        if (/Verdana/i.test(name)) {