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
f (fntRefIRef) {
      th.fntCache.put(fntRef, fntCapablty.prme);
    } ele {
      f (!fntID) {
        fntID = th.dFactry.createFntId();
      }
      fnt.cacheKey = `cacheKey_${fntID}`;
      th.fntCache.put(fnt.cacheKey, fntCapablty.prme);
    }
    aert(
      fntID && fntID.tartWth("f"),
      'The "fntID" mut be (crrectly) defned.'
    );
    
    
    fnt.ladedName = `${th.dFactry.getDcId()}_${fntID}`;
    th.tranlateFnt(preEvaluatedFnt)
      .then(tranlatedFnt => {
        f (tranlatedFnt.fntType !== undefned) {