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)

break;
      case 71: 
        if (!PDFViewerApplication.supportsIntegratedFind) {
          const findState = PDFViewerApplication.findController.state;
          if (findState) {
            PDFViewerApplication.findController.executeCommand("findagain", {
              query: findState.query,
              phraseSearch: findState.phraseSearch,
              caseSensitive: findState.caseSensitive,
              entireWord: findState.entireWord,
              highlightAll: findState.highlightAll,
              findPrevious: cmd === 5 || cmd === 12,
            });
          }
          handled = true;
        }
        break;
      case 61: 
      case 107: 
      case 187: 
      case 171: 
        if (!isViewerInPresentationMode) {
          PDFViewerApplication.zoomIn();
        }
        handled = true;
        break;
      case 173: 
      case 109: 
      case 189: 
        if (!isViewerInPresentationMode) {