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)

assert(
      args.intent,
      'PDFPageProxy._pumpOperatorList: Expected "intent" argument.'
    );
    const readableStream = this._transport.messageHandler.sendWithStream(
      "GetOperatorList",
      args
    );
    const reader = readableStream.getReader();
    const intentState = this._intentStates.get(args.intent);
    intentState.streamReader = reader;
    const pump = () => {
      reader.read().then(
        ({ value, done }) => {
          if (done) {
            intentState.streamReader = null;
            return;
          }
          if (this._transport.destroyed) {
            return; 
          }
          this._renderPageChunk(value, intentState);
          pump();