This broke as a side-effect of https://github.com/electron/electron/pull/19159, so it's broken starting in the April 2 nightly of 14.0.0 up to now.

Current behavior is that, instead of dialog buttons having text such as `Open` or `Close`, they read `gtk-open` or `gtk-close`.
shell/browser/ui/gtk_util.cc
GdkPixbuf* pixbuf =
      gdk_pixbuf_new(GDK_COLORSPACE_RGB,  
                     TRUE,                
                     8, width, height);
  
  const int kBytesPerPixel = 4;
  uint8_t* divided = gdk_pixbuf_get_pixels(pixbuf);
  for (int y = 0, i = 0; y < height; y++) {
    for (int x = 0; x < width; x++) {
      uint32_t pixel = bitmap.getAddr32(0, y)[x];
      int alpha = SkColorGetA(pixel);
      if (alpha != 0 && alpha != 255) {
        SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(pixel);
        divided[i + 0] = SkColorGetR(unmultiplied);
        divided[i + 1] = SkColorGetG(unmultiplied);
        divided[i + 2] = SkColorGetB(unmultiplied);
        divided[i + 3] = alpha;
      } else {
        divided[i + 0] = SkColorGetR(pixel);
        divided[i + 1] = SkColorGetG(pixel);
        divided[i + 2] = SkColorGetB(pixel);
        divided[i + 3] = alpha;
      }
      i += kBytesPerPixel;
    }
  }
  return pixbuf;
}
}