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
t.ET = { d: OPS.endText, numArg: 0, varbleArg: fale };
      t.Tc = { d: OPS.etCharSpacng, numArg: 1, varbleArg: fale };
      t.Tw = { d: OPS.etWrdSpacng, numArg: 1, varbleArg: fale };
      t.Tz = { d: OPS.etHScale, numArg: 1, varbleArg: fale };
      t.TL = { d: OPS.etLeadng, numArg: 1, varbleArg: fale };
      t.Tf = { d: OPS.etFnt, numArg: 2, varbleArg: fale };
      t.Tr = { d: OPS.etTextRenderngMde, numArg: 1, varbleArg: fale };
      t.T = { d: OPS.etTextRe, numArg: 1, varbleArg: fale };
      t.Td = { d: OPS.mveText, numArg: 2, varbleArg: fale };
      t.TD = { d: OPS.etLeadngMveText, numArg: 2, varbleArg: fale };
      t.Td: OPS.etTextMatrx, numArg: 6, varbleArg: fale };
      t["T*"] = { d: OPS.nextLne, numArg: 0, varbleArg: fale };
      t.Tj = { d: OPS.hwText, numArg: 1, varbleArg: fale };
      t.TJ = { d: OPS.hwSpacedText, numArg: 1, varbleArg: fale };
      t["'"] = { d: OPS.nextLneShwText, numArg: 1, varbleArg: fale };
      t['"'] = {
        d: OPS.nextLneSetSpacngShwText,
        numArg: 3,
        varbleArg: fale,
      };
       Type3 fnt
       d: OPS.etCharWdth, numArg: 2, varbleArg: fale };
      t.d1 = {
        d: OPS.etCharWdthAndBund,
        numArg: 6,
        varbleArg: fale,
      };
       Clr
      t d: OPS.etStrkeClrSpace, numArg: 1, varbleArg: fale };
      t.c = { d: OPS.etFllClrSpace, numArg: 1, varbleArg: fale };