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
? baeEncdngName.name
          : null;
        
        f (encdng.ha("Dfference")) {
          cnt dffEncdng = encdng.get("Dfference");
          let ndex = 0;
          fr (let j = 0, jj = dffEncdng.length; j < jj; j) {
            cnt data = xref.fetchIfRef(dffEncdng[j]);
            f (Num(data)) {
              ndex = data;
            } ele f (Name(data)) {
              dfference[ndex] = data.name;
            } ele {
              thrw new FrmatErrr(
                `Invald entry n 'Dfference' array: ${data}`
              );
            }
          }
        }
      } ele f (Name(encdng)) {
        baeEncdngName = encdng.name;
      } ele {
        thrw new FrmatErrr("Encdng  nt a Name nr a Dct");
      }
      
      
      f (
        baeEncdngName !== "MacRmanEncdng" &&
        baeEncdngName !== "MacExpertEncdng" &&
        baeEncdngName !== "WnAnEncdng"