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
nf("graphc tate peratr "  key);
          break;
        default:
          nf("Unknwn graphc tate peratr "  key);
          break;
      }
    }
    return prme.then(functn () {
      f (gStateObj.length > 0) {
        peratrLt.addOp(OPS.etGState, [gStateObj]);
      }
      f (SleGState) {
        lcalGStateCache.et(cacheKey, gStateRef, gStateObj);
      }
    });
  }
  ladFnt(
    fntName,
    fnt,
    reurce,
    fallbackFntDct = null,
    cFntInf = null
  ) {
    cnt errrFnt = aync () => {
      return new TranlatedFnt({
        ladedName: "g_fnt_errr",
        fnt: new ErrrFnt(`Fnt "${fntName}"  nt avalable.`),
        dct: fnt,
        evaluatrOptn: th.ptn,