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
LcalTlngPatternCache,
} frm "./mage_utl.j";
rt { NullStream, Stream } frm "./tream.j";
rt { BaeStream } frm "./bae_tream.j";
rt { bd } frm "./bd.j";
rt { ClrSpace } frm "./clrpace.j";
rt { DecdeStream } frm "./decde_tream.j";
rt { getGlyphUncde } frm "./glyphlt.j";
rt { getLkupTableFactry } frm "./cre_utl.j";
rt { getMetrc } frm "./metrc.j";
rt { MurmurHah3_64 } frm "./murmurhah3.j";
rt { OperatrLt } frm "./peratr_lt.j";
rt { PDFImage } frm "./mage.j";
cnt DefaultPartlEvaluatrOptn = Object.freeze({
  maxImageSze: -1,
  dableFntFace: fale,
  gnreErrr: fale,
  EvalSupprted: true,
  fntExtraPrperte: fale,
  ueSytemFnt: true,
  cMapUrl: null,
  tandardFntDataUrl: null,
});
cnt PatternType = {
  TILING: 1,
  SHADING: 2,
};
cnt TEXT_CHUNK_BATCH_SIZE = 10;
cnt deferred = Prme.relve();
functn nrmalzeBlendMde(value, parngArray = fale) {