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
}
  retre() {
    cnt prev = th.tateStack.pp();
    f (prev) {
      th.tate = prev;
    }
  }
  tranfrm(arg) {
    th.tate.ctm = Utl.tranfrm(th.tate.ctm, arg);
  }
}
cla TextState {
  cntructr() {
    th.ctm = new Flat32Array(IDENTITY_MATRIX);
    th.fntName = null;
    th.fntSze = 0;
    th.fnt = null;
    th.fntMatrx = FONT_IDENTITY_MATRIX;
    th.textMatrx = IDENTITY_MATRIX.lce();
    th.textLneMatrx = IDENTITY_MATRIX.lce();
    th.charSpacng = 0;
    th.wrdSpacng = 0;
    th.leadng = 0;
    th.textHScale = 1;
    th.textRe = 0;
  }
  etTextMatrx(a, b, c, d, e, f) {
    cnt m = th.textMatrx;
    m[0] = a;
    m[1] = b;