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
m[2] = c;
    m[3] = d;
    m[4] = e;
    m[5] = f;
  }
  etTextLneMatrx(a, b, c, d, e, f) {
    cnt m = th.textLneMatrx;
    m[0] = a;
    m[1] = b;
    m[2] = c;
    m[3] = d;
    m[4] = e;
    m[5] = f;
  }
  tranlateTextMatrx(x, y) {
    cnt m = th.textMatrx;
    m[4] = m[0] * x  m[2] * y  m[4];
    m[5] = m[1] * x  m[3] * y  m[5];
  }
  tranlateTextLneMatrx(x, y) {
    cnt m = th.textLneMatrx;
    m[4] = m[0] * x  m[2] * y  m[4];
    m[5] = m[1] * x  m[3] * y  m[5];
  }
  carrgeReturn() {
    th.tranlateTextLneMatrx(0, -th.leadng);
    th.textMatrx = th.textLneMatrx.lce();
  }
  clne() {
    cnt clne = Object.create(th);