STR:
  - Go to https://mozilla.github.io/pdf.js/web/viewer.html
  - Click on "Open File" and open a pdf

The `Download` button and the `Current view` one just disappear.
I can reproduce this bug with Firefox nightly, Chrome stable and Epiphany on debian.
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) {