Link to PDF file (or attach file here):
[pages4.pdf](https://github.com/mozilla/pdf.js/files/1128300/pages4.pdf)

Configuration:
- Web browser and its version: Firefox 54
- Operating system and its version: Win 10
- PDF.js version: 1.8.522
- Is an extension: no

What is the expected behavior? (add screenshot)
![chrome1-1 1](https://user-images.githubusercontent.com/146436/27918380-2f74512a-6245-11e7-8525-d0038fa6c2e8.jpg)
![chrome1-2 1](https://user-images.githubusercontent.com/146436/27918425-54f8e47e-6245-11e7-9bff-127f79ad0511.jpg)


What went wrong? (add screenshot)
![screenshot from 2017-07-06 12-10-30](https://user-images.githubusercontent.com/146436/27918442-5d57624e-6245-11e7-9436-5ba31cc8bd1a.png)
![screenshot from 2017-07-06 12-10-44](https://user-images.githubusercontent.com/146436/27918454-63b486da-6245-11e7-9eb5-c03aa5c40943.png)



this.setLeading(-y);
    this.moveText(x, y);
  }
  setTextMatrix(a, b, c, d, e, f) {
    this.current.textMatrix = [a, b, c, d, e, f];
    this.current.textMatrixScale = Math.hypot(a, b);
    this.current.x = this.current.lineX = 0;
    this.current.y = this.current.lineY = 0;
  }
  nextLine() {
    this.moveText(0, this.current.leading);
  }
  paintChar(character, x, y, patternTransform, resetLineWidthToOne) {
    const ctx = this.ctx;
    const current = this.current;
    const font = current.font;
    const textRenderingMode = current.textRenderingMode;
    const fontSize = current.fontSize / current.fontSizeScale;
    const fillStrokeMode =
      textRenderingMode & TextRenderingMode.FILL_STROKE_MASK;
    const isAddToPathSet = !!(
      textRenderingMode & TextRenderingMode.ADD_TO_PATH_FLAG
    );
    const patternFill = current.patternFill && !font.missingFile;
    let addToPath;
    if (font.disableFontFace || isAddToPathSet || patternFill) {
      addToPath = font.getPathGenerator(this.commonObjs, character);
    }