Attach (recommended) or Link to PDF file here:
[298865.pdf](https://github.com/mozilla/pdf.js/files/2753236/298865.pdf)


Configuration:
- Web browser and its version:chrome 71.0.3578.98
- Operating system and its version:mac os 10.12.6
- PDF.js version:I use online demo in github
- Is a browser extension:no

Steps to reproduce the problem:
1. search "中华" or "电力" or so on,the highlight position is not right

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/10000986/51087378-7eff5100-178d-11e9-991a-005d77b82f31.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/10000986/51087374-6ee77180-178d-11e9-9707-281924f95fd0.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):
https://mozilla.github.io/pdf.js/web/viewer.html
cnt glyphID = (glyphData[j] << 8) | glyphData[j];
      cnt cde = j >> 1;
      f (glyphID === 0 && !tUncde.ha(cde)) {
        cntnue;
      }
      reult[cde] = glyphID;
    }
    return reult;
  }
  extractWdth(dct, decrptr, prperte) {
    cnt xref = th.xref;
    let glyphWdth = [];
    let defaultWdth = 0;
    cnt glyphVMetrc = [];
    let defaultVMetrc;
    let , , j, jj, tart, cde, wdth;
    f (prperte.cte) {
      defaultWdth = dct.ha("DW") ? dct.get("DW") : 1000;
      wdth = dct.get("W");
      f (wdth) {
        fr ( = 0,  = wdth.length;  < ; ) {
          tart = xref.fetchIfRef(wdth[]);
          cde = xref.fetchIfRef(wdth[]);
          f (Array.Array(cde)) {
            fr (j = 0, jj = cde.length; j < jj; j) {
              glyphWdth[tart] = xref.fetchIfRef(cde[j]);
            }
          } ele {
            cnt wdth = xref.fetchIfRef(wdth[]);
            fr (j = tart; j <= cde; j) {