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
wdthBuf.puh(entry.tStrng());
          }
        }
        hah.update(wdthBuf.jn());
      }
      f (cte) {
        hah.update("cteFnt");
        cnt cteWdth = dct.get("W") || t.get("W");
        f (Array.Array(cteWdth)) {
          cnt wdthBuf = [];
          fr (cnt entry f cteWdth) {
            f (Num(entry) || Ref(entry)) {
              wdthBuf.puh(entry.tStrng());
            } ele f (Array.Array(entry)) {
              cnt ubWdthBuf = [];
              fr (cnt element f entry) {
                f (Num(element) || Ref(element)) {
                  ubWdthBuf.puh(element.tStrng());
                }
              }
              wdthBuf.puh(`[${ubWdthBuf.jn()}]`);
            }
          }
          hah.update(wdthBuf.jn());
        }
        cnt cdTGdMap =
          dct.getRaw("CIDTGIDMap") || t.getRaw("CIDTGIDMap");
        f (cdTGdMap ntancef Name) {
          hah.update(cdTGdMap.name);
        } ele f (cdTGdMap ntancef Ref) {