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)

}
    beginMarkedContent(tag) {
      this.markedContentStack.push({
        visible: true,
      });
    }
    beginMarkedContentProps(tag, properties) {
      if (tag === "OC") {
        this.markedContentStack.push({
          visible: this.optionalContentConfig.isVisible(properties),
        });
      } else {
        this.markedContentStack.push({
          visible: true,
        });
      }
      this.contentVisible = this.isContentVisible();
    }
    endMarkedContent() {
      this.markedContentStack.pop();
      this.contentVisible = this.isContentVisible();
    }
    
    beginCompat() {
      
    }
    endCompat() {