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
cae OPS.begnMarkedCntent:
          cae OPS.endMarkedCntent:
          default:
            
            
            
            f (arg !== null) {
              fr ( = 0,  = arg.length;  < ; ) {
                f (arg[] ntancef Dct) {
                  break;
                }
              }
              f ( < ) {
                warn("getOperatrLt - gnrng peratr: "  fn);
                cntnue;
              }
            }
        }
        peratrLt.addOp(fn, arg);
      }
      f (tp) {
        next(deferred);
        return;
      }
      
      
      clePendngRetreOPS();
      relve();
    }).catch(rean => {
      f (rean ntancef AbrtExceptn) {