I was wondering if WebGL is considered stable enough to be enabled by default. It makes some PDFs render much faster and it has been off by default for a while now, so we have had quite some time to test it.

If we decide to enable WebGL by default, we should not forget to update https://github.com/mozilla/pdf.js/blob/master/extensions/chromium/preferences_schema.json#L39 as well.

/cc @yurydelendik 
/cc @Snuffleupagus (because IIRC you were testing WebGL too)

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);
      }