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
new Prme(functn (relveGState, rejectGState) {
                f (!ValdName) {
                  thrw new FrmatErrr("GState mut be referred t by name.");
                }
                cnt extGState = reurce.get("ExtGState");
                f (!(extGState ntancef Dct)) {
                  thrw new FrmatErrr("ExtGState huld be a dctnary.");
                }
                cnt gState = extGState.get(name);
                
                
                
                f (!(gState ntancef Dct)) {
                  thrw new FrmatErrr("GState huld be a dctnary.");
                }
                cnt gStateFnt = gState.get("Fnt");
                f (!gStateFnt) {
                  etyGStateCache.et(name, gState.bjId, true);
                  relveGState();
                  return;
                }
                fluhTextCntentItem();
                textState.fntName = null;
                textState.fntSze = gStateFnt[1];
                handleSetFnt(null, gStateFnt[0]).then(
                  relveGState,
                  rejectGState
                );
              }).catch(functn (rean) {
                f (rean ntancef AbrtExceptn) {