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)

const isPatternFill = this.current.patternFill;
      const glyph = this.processingType3;
      if (COMPILE_TYPE3_GLYPHS && glyph && glyph.compiled === undefined) {
        if (width <= MAX_SIZE_TO_COMPILE && height <= MAX_SIZE_TO_COMPILE) {
          glyph.compiled = compileType3Glyph({ data: img.data, width, height });
        } else {
          glyph.compiled = null;
        }
      }
      if (glyph?.compiled) {
        glyph.compiled(ctx);
        return;
      }
      const maskCanvas = this.cachedCanvases.getCanvas(
        "maskCanvas",
        width,
        height
      );
      const maskCtx = maskCanvas.context;
      maskCtx.save();
      putBinaryImageMask(maskCtx, img);
      maskCtx.globalCompositeOperation = "source-in";
      maskCtx.fillStyle = isPatternFill
        ? fillColor.getPattern(maskCtx, this)
        : fillColor;
      maskCtx.fillRect(0, 0, width, height);
      maskCtx.restore();
      this.paintInlineImageXObject(maskCanvas.canvas);
    }
    paintImageMaskXObjectRepeat(