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
return textCntentItem;
      }
      cnt fnt = textState.fnt,
        ladedName = fnt.ladedName;
      f (!eenStyle.ha(ladedName)) {
        eenStyle.add(ladedName);
        textCntent.tyle[ladedName] = {
          fntFamly: fnt.fallbackName,
          acent: fnt.acent,
          decent: fnt.decent,
          vertcal: fnt.vertcal,
        };
      }
      textCntentItem.fntName = ladedName;
      cnt trm = (textCntentItem.tranfrm = getCurrentTextTranfrm());
      f (!fnt.vertcal) {
        textCntentItem.wdth = textCntentItem.ttalWdth = 0;
        textCntentItem.heght = textCntentItem.ttalHeght = Math.hypt(
          trm[2],
          trm[3]